Math 4

Measurement of weight

Look at these two objects and guess which one is
lighter.

Tomato is lighter than pumpkin. But in some cases, Tomato Pumpkin
it is very difficult which object is lighter and which
one is heavier.

To measure the weight of such objects, we use pan balance, spring balance,
dial balance, etc.

Weight of an object is measured in milligram, Short form of kilogram is kg
gram and kilogram. Short form of gram is gm
Short form of milligram is mg
Heavier objects are measured in kilogram (kg)
and lighter objects are measured in gram (gm).

Some commonly used blocks to measure the weight are:

Conversion of units of weight

To convert the units of weight, let’s remember their relation.

Example 1: 1000 mg = 1 gm
1000 gm = 1 kg
Convert 2 gm into milligram.
Solution: I understand, to convert gm
2 gm = 2 × 1000 mg into mg, I have to multiply
= 2000 mg
by 1000.

Oasis School Mathematics Book-4 201

Example 2: 1 kg = 1000 gm
3 kg = 3 × 1000 gm
Convert 3 kg 440 gm into
gram.
Solution:
= 3 × 1000 gm + 440 gm
= 3000 gm + 440 gm
= 3440 gm

Example 3: To convert mg into gm, I have
to divide mg by 1000.
Convert 350 mg into gram.

Solution:

= 350 gm
1000

= 35 kgm 35 = 0.35
100 100

= 0.35 gm

Example 4: 1000 gm = 1 kg
1 gm = 1 kg
Convert 600 gm into kg.
1000

Solution: 600 gm = 600 kg
1000
600 gm = 600 kg
1000

= 6 kg
10

= 0.6 kg

Example 5: Example 6:

Convert 16 gm 450 mg into gm. Convert 13 kg 750 gm into kg.

Solution: Solution:

16 gm 450 mg 13 kg 750 gm

= 16 gm + 450 gm = 13 kg + 750 kg
1000 1000

= 16 gm + 45 gm = 13 kg + 0.75 kg
100
= 13.75 kg
= 16 gm + 0.45 gm

= 16.45 gm 750 75
1000 100
= = 0.75

202 Oasis School Mathematics Book-4

Example 7:

Convert into gm and mg: 3240 mg. 1000) 3240 (3 gm
Solution:
- 3000 mg
3240 mg gm
240
= 3240 gm Quotient mg
1000
Remainder

= 3 gm 240 mg

Example 8: 1000) 2560 (3 kg

Convert into kg and gm: 2560 gm - 2000 gm
kg
Solution: 560
2560 gm = 2560 kg Quotient gm

1000 Remainder
= 2 kg 560 gm

Exercise 9.3

1. Convert the following into milligram (mg).

a. 5 gm b. 12 gm c. 25 gm 150 mg
f. 320 gm 550 mg
d. 18 gm 356 mg e. 7 gm 15 mg c. 15 kg
f. 13 kg 720 gm
2. Convert the following into gram (gm).
c. 25 gm 350 mg
a. 3 kg b. 7 kg f. 316 gm 200 mg
c. 5 kg 200 gm
d. 5 kg 450 gm e. 7 kg 840 gm f. 17 kg 860 gm

g. 18 kg 550 gm c. 12438 gm

3. Convert the following into gm. c. 3238 mg

a. 300 mg b. 415 mg

d. 18 gm 450 mg e. 105 gm 600 mg

4. Convert the following into kilogram (kg).

a. 500 gm b. 750 gm

d. 7 kg 640 gm e. 13 kg 570 gm

g. 85 kg 450 gm

5. Convert the following into kg and gm.

a. 4325 gm b. 6056 gm

d. 2426 gm e. 8538 gm

6. Convert the following into gm and mg.

a. 3524 mg b. 4732 mg

d. 8438 mg e. 9838 mg

Oasis School Mathematics Book-4 203

Answers:

1. a. 5000 mg b. 12000 mg c. 25150 mg d. 18356 mg e. 7015 mg f. 320550 mg

2. a. 3000 gm b. 7000 gm c. 15000gm d. 5450 gm e. 7840 gm f. 13720 gm

g. 18550 gm 3. a. 0.3 gm b. 0.415 gm c. 25.35 gm d. 18.45 gm e. 105.6 gm
f. 316.2 gm 4. a. 0.5 kg
f. 17.86 kg g. 85.45 kg b. 0.75 kg c. 5.2 kg d. 7.64 kg e. 13.57 kg

5. a. 4 kg 325 gm b. 6 kg 56 gm c. 12 kg 438 gm

d. 2 kg 426 gm e. 8 kg 538 gm 6. a. 3 gm 524 mg b. 4 gm 732 mg c. 3 gm 238 mg

d. 8 gm 438 mg e. 9 gm 838 mg

Quick method of conversion: 1kg 164 gm
1 gm 325 mg

1325 mg 1164 gm

Class Assignment

Convert into mg Convert into gm
1 gm 325 mg = 1325 mg 1 kg 65 mg = 1065 gm
1 gm 85 mg = ................... 1 kg 225 mg = ................... gm
1 gm 320 mg = ................... 1 kg 350 mg = ................... gm
1 gm 450 mg = ................... 1 kg 465 mg = ................... gm
1 gm 650 mg = ................... 1 kg 340 mg = ................... gm
1 gm 50 mg = ................... 1 kg 750 mg = ................... gm

1350 mg 1450 gm

1gm 350 mg 1kg 450 gm

Convert into gm and mg. Convert into gm and kg.
1350 mg = 1 gm 350 mg 1450 gm = 1 kg 450 gm
1060 mg = ................... 1665 gm = ................... gm
1095 mg = ................... 1785 gm = ................... gm
1625 mg = ................... 1060 gm = ................... gm
1892 mg = ................... 1095 gm = ................... gm
1950 mg = ................... 1200 gm = ................... gm

204 Oasis School Mathematics Book-4

Addition and subtraction of weight

Study the given examples carefully and get the idea of addition and subtraction

of weight properly. Steps:

Example 1: • Add mg

Add: gm mg 665 mg + 824 mg = 1489 mg
kg 750 665 = 1gm 489 mg
670 824 Carry over: 1 gm
15 • Add gm:
750 gm + 670 gm = 1420 gm
+ 18

33 1420 1489 • Add carry over : 1420 gm + 1 gm = 1421
33 1421 489 gm = 1 kg 421 gm
34 421 489
carry over 1 kg
• Add kg : (15 + 18) kg = 33 kg

• Add kg with carry over, 33 kg + 1 kg = 34

kg

Example 2:

Subtract: Steps:
kg gm mg
• In mg,
1175 175 < 325
Borrow 1 gm to mg leaving 249 gm, now 1
55 250 175
- 24 845 325 gm 175 mg = 1175 mg
Subtract mg, 1175 mg - 325 mg = 850 mg
30 404 850 • In gm,

249 < 845

Borrow 1 kg leaving 54 kg. Now, 1 kg 249 gm

= 1249 gm

Subtract gm : (1249 - 845) gm = 404 gm

Subtract kg : (54 - 24) kg = 30 kg

Exercise 9.4 b. kg gm
18 680
1. Add: + 13 550
a. kg gm
8 470
+ 15 920

c. gm mg d. gm mg
320 816 424 750
+ 124 930 + 216 480

Oasis School Mathematics Book-4 205

e. kg gm mg f. kg gm mg
5 750 680 15 663 571
+ 9 570 670 + 16 837 749

g. kg gm mg h. kg gm mg
5 750 680 25 718 540
+ 9 570 670 + 18 615 720

2. Subtract: b. kg gm
a. kg gm 28 325
15 470 - 16 725
- 8 520
d. gm mg
c. gm mg 243 225
127 540 - 128 843
- 108 870
f. kg gm mg
e. kg gm mg 15 454 358
8 332 546 - 7 816 713
- 3 886 648
h. kg gm mg
g. kg gm mg 35 316 524
22 645 367 - 17 845 753
- 16 815 763

3. Add or subtract:
a. 25 kg 350 g, + 14 kg 830 gm
b. 8 kg 726 gm 354 mg + 7 kg 553 gm 705 mg
c. 13 kg 616 gm 425 mg + 17 kg 825 gm 813 mg
d. 5 kg 342 gm - 2 kg 816 gm
e. 17 gm 433 mg - 11 gm 844 mg
f. 8 kg 654 gm 355 mg - 5 kg 850 gm 460 mg
g. 12 kg 145 gm 320 mg - 7 kg 420 gm 414 mg

206 Oasis School Mathematics Book-4

4. a. Ram bought 9 kg 450 gm potatoes and 2 kg 840 gm of onions. Find
the total weight of vegetables that he bought.

b. From a sack of 30 kg of rice, 12 kg 450 gm of rice is sold. How much
rice is left?

c. A man bought 12 kg 450 gm of apples and 18 kg 830 gm of oranges.
How much fruit did he buy altogether?

Consult your teacher.

Measurement of capacity

Units of measurement of capacity
Look at these two vessels and guess which one
holds more water?
Clearly, a bucket can hold more water than a
bottle. i.e. the capacity of a bucket is more than
that of a bottle.
Hence, the amount of liquid that a vessel can
hold in it is called its capacity.

Capacity of vessel is measured in litres (l) and millilitres (ml).
Capacity of vessel is measured by:

Conversion of units of capacity

1 l = 1000 ml Remember !
• Short form of litre is l and that of millilitre is ml.

Example 1: I understand, I have to multiply
litre by 1000 to convert it into ml.
Convert 3 litres into millilitres.
Solution:
3 litres
= 3 × 1000 ml
= 3000 ml

Oasis School Mathematics Book-4 207

Example 2:

Convert 5 litres 370 ml into ml.
Solution:

5 l 370 ml

= 5 × 1000 ml + 370 ml

= 5000 ml + 370 ml

= 5370 ml

Example 3:

Convert 2250 ml into litres (l) and millilitres (ml).

Solution: 1000 ml = 1 litre

2250 ml 1 ml = 1 l
1000
2250
= 2250 l 2250 ml = 1000 l
1000

= 2l 250 ml 1000) 2250 (2 l

- 2000 ml
l
250
Quotient

Remainder ml

Example 4: I have the idea about division
of a number by 100.
Convert 5l 350 ml into litres.

Solution:

5 l 350 ml

= 5l + 350 l
1000

= 5l + 35 l
100

= 5 l + 0.35 l

= 5.35l

208 Oasis School Mathematics Book-4

Exercise 9.5

1. Convert into millilitre (ml).

a. 6 l b. 8 l c. 2 l 250 ml d. 6 l 315 ml

e. 7 l 850 ml f. 8 l 910 ml

2. Convert into litre (l) and millilitre (ml).
a. 1550 ml b. 2240 ml c. 3480 ml d. 4500 ml
e. 5050 ml f. 6740 ml g. 7050 ml

3. Convert into litre (l)

a. 2 l 250 ml b. 5 l 500 ml c. 4 l 650 ml
f. 12 l 200 ml
d. 10 l 10 ml e. 6 l 400 ml

Answers: b. 8000 ml c. 2250 ml d. 6315 ml e. 7850 ml f. 8910 ml
1. a. 600 ml b. 2l 240 ml c. 3l 480 ml d. 4l 500 ml e. 5l 50 ml f. 6l 740 ml
2. a. 1 l 550 ml 3. a. 2.25 l b. 5.5 l c. 4.65 l d. 10.01 l
f. 12.2 l
g. 7l 50 ml
e. 6.4 l

Addition and subtraction of capacity

Study the given examples carefully and get the idea of addition and subtraction
of capacity.

Example 1: ml Steps:
Add: 676 • Add ml.
l 584 (676 + 584) ml = 1260 ml
15 1260 = 1 l 260 ml, carry over 1 l
+ 18 260 • Add litres (l)
33 15 + 18 = 33 l
34 • Add with carry over:
33 l + 1 l = 34 l

Oasis School Mathematics Book-4 209

Example 2: ml Steps:
3501350 In ml, 350 < 824
Subtract: • Borrow 1 l from 22 l leaving 21 l. Now, 1
l 1l 824
22 21 l 350 ml = 1350 ml
- 16 526 • Subtract ml: (1350 - 824) ml = 426 ml
5 • Subtract litres.
(21 - 16) l = 5 l.

Quick method of conversion: 1460 ml
1 l 450 ml

1450 ml 1 l 460 ml

Class Assignment Convert into l and ml

Convert into ml. 1460 ml = 1 l 460 ml
1 litre 450 ml = 1450 ml
1 l 350 ml = ................... 1550 ml = ......... l .......... ml
1 l 540 ml = ...................
1 l 320 ml = ................... 1760 ml = ......... l .......... ml
1 l 650 ml = ...................
1 l 380 ml = ................... 1880 ml = ......... l .......... ml
1 l 90 ml = ...................
1900 ml = ......... l .......... ml

1600 ml = ......... l .......... ml

1080 ml = ......... l .......... ml

210 Oasis School Mathematics Book-4

Exercise 9.6

1. Add: ml b. l ml c. l ml
820 16 726 137 632
a. l 525 + 18 530 + 96 523
7
+ 6 e. l ml f. l ml
128 736 324 713
d. l ml + 26 848 + 107 389
15 680
+ 13 576 b. l ml c. l ml
36 350 45 540
2. Subtract: - 15 678 - 16 875

a. l ml
53 225
- 16 875

d. l ml e. l ml f. l ml
35 415 156 436 216 250
- 15 930 - 128 712 - 150 850

3. Add or subtract: b. 16 l 877 ml + 12 l 512 ml
a. 15 l 350 ml + 18 l 833 ml

c. 210 l 776 ml + 15 l 345 ml d. 21 l 225 ml - 12 l 375 ml

e. 58 l 314 ml - 18 l 653 ml f. 124 l 52 ml - 65 l 278 ml

4. a. A bucket contains 17 l 630 ml of water and another bucket contains
12 l 448 ml of water. How much water is there in the two buckets?

b. A shopkeeper sold 12 l 675 ml of mustrad oil and 32 l 550 ml of
sunflower oil. How much oil did he sell altogether?

c. A man had 25 l 350 ml of milk. He sold 8 l 635 ml of milk. How much
milk is left with him now?

d. The capacity of a bucket is 18 l 650 ml. It has 8 l 875 ml of water. How
much more water is needed to fill it?

Consult your teacher.

Oasis School Mathematics Book-4 211

Objective Questions 1mm 10mm
km
Colour the correct alternatives.
1. 100 cm is equal to

1m

2. Suitable unit of measurement of the length of a pencil is
cm metre

3. 215 cm is equal to 21 m 5cm 21.5m
2 m 15 cm

4. Suitable unit of measurement of the weight of an orange is

kg gm mg

5. Estimated capacity of a bucket is

1 litre 100 ml 15 litres

6. 3560 gm is equal to

35 kg 60 gm 356 kg 3 kg 560 gm

7. 1560 ml is equal to 15.6 litre 156 litres
1.56 litre

8. Which of the following relation is not true?

1 litre = 100 ml 1 kg = 10000 gm 1m = 1000 cm

Number of correct answers
212 Oasis School Mathematics Book-4

Unit Test b. 1 ml = ............l Full marks -24
3
1. Fill in the blanks.
a. 1 kg = ............gm c. 1 km = ............m.
d. 1m = ............cm.
e. 1mg = ............gm. f. 1 l = ............ml.

2. Convert the following as indicated: 5
a. 1480 m into km and m 3×2=6
b. 2 kg 100 gm into kg 2×2=4
c. 5 km 375 m into metre (m)
d. 4325 gm into kg and gm
e. 5700 ml into litre and millilitre

3. Add:
a. 15kg 750 gm + 6 kg 650 gm
b. 5l 820 ml + 3l + 240 ml
c. 144m 25cm + 284m 85cm

4. Subtract:

a. kg gm mg b. litres ml
22 645 350 540 620
- 16 840 750 - 280 940

5. a. A man bought 12 kg 650 gm of apples and 18 kg 750 gm 3 × 2 = 6
of oranges. How much fruit did he buy altogether?

b. A man has 35 m 45 cm of cloth. He sold 12 m 75 cm cloth.
How much cloth left with him?

c. A man had 85l 250ml of milk. He sold 39l 750ml of milk.
How much milk is left with him?

Oasis School Mathematics Book-4 213

UNIT

10 Perimeter, Area
and Volume

12 Estimated Teaching Hours: 13
93

6

Contents • Perimeter of plane figure
• Perimeter of rectangle and square
• Area of plane figures by counting unit

square
• Area of rectangle and square using formula
• Volume of cube and cuboid by counting

unit cubes and by using formula.

Expected Learning Outcomes

Upon completion of the unit, students will be able
to develop the following competencies:

• To find the perimeter of plane figures
• To find the perimeter of rectangle and square by

using formula
• To find the area of rectangle and square
• To find the volume of cube and cuboid

Materials Required: Paper model of plane shape, model of cube, cuboid, etc.

214 Oasis School Mathematics Book-4

Perimeter

Let's observe the quadrilateral ABCD to get an idea about perimeter.

Here, length of AB = 4 cm 4 cm
AB

length of BC = 3 cm 2 cm 3 cm
length of CD = 5 cm D C
length of AD = 2 cm
5 cm

Total length of outer boundary of quadrilateral ABCD = 4 cm + 3 cm + 5 c m + 2 cm

= 14 cm

Perimeter of quadrilateral ABCD = 14 cm

Hence, the perimeter of a plane figure is the total length of its outer boundary.

I understand! Total length of outer
boundary is the perimeter of a plane

figure.

Again, in DABC, its outer boundary is formed A
by AB, BC and AC. BC
\ Its perimeter = (AB + BC + AC)

Class Assignment

1. Calculate the perimeter of given figures.

a. A b. P c. A
4cm
5cm 5cm 2 cm S 4 cm

Q
4 cm
B 6cm C 3 cm 5 cm D
B 2 cm
R 2 cm

Perimeter Perimeter C
= AB + BC + AC
= ....... + ....... + ....... Perimeter
= .......
= PQ + QR + RS + PS = AB + BC + CD + AD

= ....... + ....... + ....... + ....... = ....... + ....... + ....... + .......

= ....... = .......

Oasis School Mathematics Book-4 215

a. M 4 cm N b. P 2 cm Q
3 cm
10 cm 2 cm 4 cm O 3 cm

P 6 cm 5 cm

R 3 cm S
2 cm

Perimeter U 5 cm T
= MN + NO + OP + PM
= ....... + ....... + ....... + ....... Perimeter
= .......
= PQ + QR + RS + ST + TU + PU

= ....... + ....... + ....... + ....... + ....... + .......

= .......

Exercise 10.1

1. Findtheperimeterofthefollowingclosedfigures:
a. b.

3 cm 5 cm

2 cm 3cm 3 cm 6 cm
4 cm
c. 4 cm d. 2 cm
6 cm
5 cm 3 cm
4 cm
5 cm

2. Findtheperimeterofgivenfigures: 6 cm 2 cm
9 cm
12cm 15 cm

5 cm
12 cm
10 cm
12 cm
5 cm

12cm 15 cm 9 cm

216 Oasis School Mathematics Book-4

3. Find the perimeter of the given shape. Each square is unit square having each
side 1 unit.
a. b.

c. d.

e. f.

4. Usingarulermeasureeachsideofthegivenfigureandfindtheperimeter.

P A B

a. b.

FE

Q R HG DC

a. A c. P

CB QS

ED R
F
Consult your teacher.

Perimeter of a rectangle

ABCD is a rectangle. Its lengths are AB and
CD. Its breadths are AD and BC.

\ AB = DC = l

AD = BC = b

Now, perimeter of rectangle ABCD = AB + BC + DC + AD

= l + b + l + b

= 2 l + 2b

= 2( l + b)

\ Perimeter of a rectangle = 2(l + b)

Oasis School Mathematics Book-4 217

Example :

Find the perimeter of rectangle ABCD.

Solution:

Here, l = 8 cm
b = 2 cm
We have, Perimeter

= 2 (l + b)

= 2 ( 8 + 2) Operation in the bracket

= 2 × 10

= 20 cm All sides of square are
equal.

Perimeter of a square

ABCD is a square. Its four sides are AB, BC, CD and
AD.

All sides of a square are equal.

\ AB = BC = CD = AD = l

Perimeter of the square = AB + BC + CD + AD

= l + l + l + l

= 4l \ Perimeter of the square = 4l
Example :

Find the perimeter of a square ABCD.
Solution:

Here length of each side of the square (l) = 5 cm

We have perimeter of a square = 4l
= 4 × 5 cm
= 20 cm

Exercise 10.2

1. Find the perimeter of the given figures (using the formula).

a. 6 cm b. 4 cm

3 cm 3 cm 4 cm 4 cm

6 cm 4 cm

218 Oasis School Mathematics Book-4

2. Find the perimeter of rectangles whose length and breadth are given below.
a. l = 5 cm, b = 4 cm b. l = 4 cm, b = 3 cm c. l = 6 cm, b = 4 cm

d. l = 8 cm, b = 3.5 cm e. l = 7 cm, b = 3 cm f. l = 3.5 cm, b = 2.5 cm

g. l = 4.5 cm, b = 3.5 cm h. l = 6.5 cm, b = 3.5 cm

3. Find the perimeter of squares whose lengths are given below.

a. l = 3 cm b. l = 4 cm c. l = 5 cm d. l = 7 cm

e. l = 3.5 cm f. l = 4.5 cm g. l = 5.5 cm

Answers: b. 16 cm 2. a. 18 cm b. 14 cm c. 20 cm d. 23cm
f. 12 cm g. 16cm h. 20 cm
1. a. 18 cm b. 16cm c. 20cm d. 28 cm e. 14cm f. 18cm g. 22cm
e. 20cm

3. a. 12cm

Area

If we paste a picture on the wall, it covers some surface
of the wall. The space covered by the surface of an
object is its area.

The surface of a book is greater than that of a box so
the area of a book is greater than that of a box.

The unit of area

In the given figure, ABCD is a square. Each of its sides is 1 cm. So the area of
the square is 1 cm2 or 1 square cm.

A 1 cm B If each side of a square is 1 cm,
DC its area is 1 cm2 (square cm).

Units of area are cm² (square cm), m² ( square m) etc. The area of a figure
formed by the squares having its side 1 cm each can be obtained by counting
the number of squares.

In the given figure, 8 squares having each side of
1 cm are shaded.

Therefore, the area of the shaded part = 8 sq. cm.

Remember !

Area = 1 sq. cm.

Area = 1 sq.cm.
2

Oasis School Mathematics Book-4 219

Example :

Find the area of the given shape.

Solution:

Here, the number of complete squares = 12

Area of complete squares = 12 cm²

Number of triangles = 4

Area of 4 triangles = 4 × 1 cm²
2

= 2 cm²

Total area = 12 cm² + 2 cm² = 14 cm²

Exercise 10.3

1. Find the area of the following shapes by counting the unit squares.
a. ...... sq. cm
b. ...... sq. cm
c. ...... sq. cm
d. ...... sq. cm
e. ...... sq. cm

2. Find the area of the given shapes where = 1 cm² and = 1 cm².
2

220 Oasis School Mathematics Book-4

3. This is the model a of school. Find the area covered by different parts of the
model.

Garden

School building Swimming pool

Canteen Hostel Fun park
Parking

Consult your teacher.

Oasis School Mathematics Book-4 221

Area of rectangles and squares

The given figure ABCD is a rectangle with 40 squares having each side of 1 cm.
Area of rectangle = 40 sq. cm.

The number of squares along its length = 8

The number of squares along its breadth = 5

So the area of the rectangle = 8 × 5 sq. cm.

=l×b

\ Area of rectangle = length × breadth

In square, Area of rectangle = l × b
Area of square = l²
length = breadth

Area of square = length × breadth

= l²
Example :

Find the area of the given rectangle:

Solution: 4 cm

Here, length of the rectangle (l) = 4 cm

breadth of the rectangle (b) = 3 cm 3 cm

We have,

Area of rectangle = l × b

= 4 cm × 3 cm
= 12 cm²

Example :

Find the area of the given square:

Solution: 2 cm
2 cm
Here, length of each side (l) = 2 cm

Area of square = l²
= (2 cm)² = 4 cm²

222 Oasis School Mathematics Book-4

Exercise 10.4

1. Find the area of the following rectangles and squares using the formula:

2. Find the area of the following rectangles (using formula):

a. l = 5 cm, b = 3 cm b. l = 8 cm, b = 3 cm

c. l = 4 cm, b = 3 cm d. l = 6 cm, b = 4 cm

e. l = 7 cm, b = 4 cm f. l = 8 cm, b= 6 cm

3. Find the area of the following squares (using formula):
a. l = 6 cm b. l = 4 cm c. l = 10 cm d. l = 9 cm

e. l = 12 cm f. l = 7 cm

4. Using a ruler, measure the length and the breadth of given rectangle and
square. Also find their area.

a. b.

5. a. Find the area of a page whose length is 18 cm and breadth is 12 cm.
b. Find the area of a square whose side is 15 cm.

Answers: c. 6 sq.cm d. 9 sq.cm e. 4 sq. cm
1. a. 8 sq. cm b. 20 sq. cm e. 28 sq.cm
2. a. 15 sq.cm b. 24 sq.cm. c. 12 sq.cm d. 24 sq.cm e. 144 sq.cm f. 48 sq.cm
3. a. 36 sq.cm b. 16 sq.cm f. 49 sq.cm
4. Consult your teacher c. 100 sq.cm d. 81 sq.cm

5. a. 216 sq.cm b. 225 sq.cm

Oasis School Mathematics Book-4 223

Volume

Every object occupies some space. The space occupied by any object is the
volume.

Volume of a cube

This is a cube. It has three dimensions: length, breadth 1 cm 1 cm
and height. All dimensions of a cube are equal. If 1 cm
length, breadth and height of a cube are 1 cm each,
then the volume of the cube is 1 cubic cm or 1 cm3.

We can obtain the volume of the cube by using the formula, V = l3.

Volume of a cuboid:

This is a cuboid. It has three dimensions
length, breadth and height.

The length, breadth and height of a cuboid
are denoted by l, b and h respectively.

Volume of the cuboid = length × breadth × height

V=l×b×h

Example :

1. In the given figure, the volume of each cube is 1 cu. cm. Count the number of
cubes and find the volume of the given solid.

Remember !

All sides of a cube are equal.

Volume of cube = l3.

Volume of cuboid = l × b × h

Solution:

Here, the number of cubes having volume 1 cu. cm = 12

\ Volume of the solid = 12 cu. cm

2. Find the volume of a cuboid which has

l = 5 cm, b= 4 cm and h = 3 cm.

Solution:

Here,

l = 5 cm, b= 4 cm, h = 3 cm

We have, Volume (v) = l × b × h

= 5 × 4 × 3 cu.cm

= 60 cu.cm

224 Oasis School Mathematics Book-4

3. The given cuboid is formed from the cubes, each of them having volume
1 cu. cm. Find l, b and h and use the formula to find its volume.

Solution:

Here, No. of cubes along length = 6
length (l) = 6 cm \ l = 6 cm
breadth (b) = 2 cm

height (h) = 2 cm

We have,

Volume of the cuboid = l × b × h

= 6 × 2 × 2 cu.cm

= 24 cu. cm

Exercise 10.5

1. In the given figures, the volume of each cube is 1 cu. cm. Count the number of
cubes to find the volume of the given solids.

2. Calculate the volume of the cuboid. (using formula).

a. l = 4 cm, b = 3 cm, h = 2 cm b. l = 5 cm, b = 3 cm, h = 2 cm

c. l = 6 cm, b = 3 cm, h = 2 cm d. l = 4 cm, b = 4 cm, h = 3 cm

e. l = 8 cm, b = 7 cm, h = 6 cm f. l = 9 cm, b= 7 cm, h = 5 cm

Oasis School Mathematics Book-4 225

3. Calculate the volume of the cube (using formula).
a. l = 5 cm b. l = 4 cm c. l = 6 cm d. l = 8 cm

e. l = 10 cm f. l = 12 cm g. l = 11 cm

4. Find l, b and h of the given cuboid and find their volume:

a. b. c. d.

5. a. A cubical box has length 25 cm each. Find its volume.

b. The length, breadth and height of a room are 5 m, 4 m, and 3 m
respectively. Find its volume.

Answers: c. 4 cu.cm d. 6 cu.cm e. 5 cu.cm f. 6 cu.cm
1. a. 3 cu.cm b. 8 cu.cm c. 36 cu.cm d. 48 cu.cm e. 336 cu.cm f. 315 cu.cm
2. a. 24 cu.cm b. 30 cu.cm c. 216 cu.cm d. 512 cu.cm e. 1000 cu.cm
3. a. 125 cu.cm b. 64 cu.cm 4. a. 3 cu.cm b. 24 cu.cm c. 9 cu.cm d. 16 cu.cm
f. 1728 cu.cm g. 1331 cu.cm
5. a. 15625 cu.cm b. 60 cu.m

Activity I:
Using a ruler or measuring tape, measure each side of the following objects
and find their perimeter.
• Your desk
• Your mathematics book

• White/Black board.

Activity II:

Using ruler or measuring tape measure the length and breadth of the given
objects and using formula find the area of given objects.

Object Length (l) Breadth (b) Area (A) l × b

Your maths copy

Teacher table

Your handkerchief

Your bench

226 Oasis School Mathematics Book-4

Worksheet

Write English alphbets A, E, F, H, I, M, N and Z in the given square lined paper using
only full and half square. Find the area covered by each letter and total area covered
by your name.

Letters AE FH I NZ
Area
Oasis School Mathematics Book-4 227

Unit Test Full marks -16

1. F ind the area of the given shape, where = 1 sq. cm and = 12 sq .cm:2

2. In the given figure, volume of each cube is 1 cu. cm. Count the number of

cubes and find the volume of the given solid: 2

3. Solve the following: 2×2=4

a. Find the perimeter of a rectangle whose length and breadth are 6

cm and 4.5 cm respectively.

b. Find the perimeter of a square whose side is 7 cm.

4. Find the area of the given figures: 2×2=4
a. b.

5. Calculate the volume of the cuboid having: 2
l = 4 cm, b = 3cm, h = 2 cm 2

6. Calculate the volume of the cube having a side of 6 cm:

228 Oasis School Mathematics Book-4

Objective Questions A4 cm 4 cm

1. Perimeter of given triangle ABC is B 4 cm C

4 cm 8 cm 12 cm

2. Formula to find the perimeter of a rectangle is l ×b
l + b 2(l + b)

3. This is a figure formed by 10 unit squares. All their
sides are 1 cm. Then the perimeter of this figure is

16 units 10 units 40 units
2(l + b)
4. If 'l' is the length of each side of a square, then its area is
4l l²

5. If the area of one unit square
is 1 square unit, then the area
of the shaded part is

12 sq. units 4 sq. units 8 sq. units

6. Length and breadth of a rectangle are 12 cm and 8 cm respectively, then its
area is

96 cm² 40 cm² 144 cm²

7. Perimeter of a square is 12 cm, then the length of each side of the square is

4 cm 12 cm 3 cm

Number of correct answers

Oasis School Mathematics Book-4 229

UNIT

Graphs, Bills,

11 Temperature and Sets

12 Estimated Teaching Hours: 15
93

6

Contents • Bar graphs
• Billing
• Temperature
• Definition of sets
• Representation of sets
• Members of a set

Expected Learning Outcomes

Upon completion of the unit, students will be able to
develop the following competencies:

• To read the given bar graph
• To draw the bar graph from the given information
• To prepare the bill
• To read the temperature on the thermometer
• To measure the temperature
• To identify whether the given collection is a set or not
• To identify the odd one from the given collection
• To represent the set in different ways
• To identify whether the given object is a member of the given set or not

Materials Required: Model of bar graph, sample of bills, thermometer, etc.

230 Oasis School Mathematics Book-4

Bar graph

Data can be represented using different types of figures. A figure gives
information in an attractive manner.
Bar graph consists of bars which are vertical with equal width.

Class Assignment

1. Marks obtained by 5 students of class IV are shown in the given bar graph:

Students Prapti Rupsa Anasuya Kritika Yangchhen

Marks 25 22 30 15 20

Prapti Rupsa Anasuya Kritika Yangchhen

Students

Study the above graph carefully and answer the following questions:

a. Which student got the highest mark? ......................

b. Which student got the lowest mark? .....................

c. How much did Yangchhen obtain? .....................

d. How much did Prapti obtain? .....................

e. How much did Rupsa score? .....................

Oasis School Mathematics Book-4 231

2 The given table shows the number of students in different sections of class
IV. Draw the bar diagram to show this information:

Section A B CD E
No. of Students 40 35 45 30 32

3. The given table shows the favourite TV channel of students of class IV. Draw
the bar graph from the given information.

T.V Channel Cartoons Sports Comedy News Adventure

Number of students 8 6 10 4 6

16
14
12
10
8
6
4
2

0

Cartoons Sports Comedy News Adventures

232 Oasis School Mathematics Book-4

Exercise 11.1

1. The given graph shows the favourite game of class IV students. Study the bar
graph and answer the following questions:

45

40

35

30

25

20

15

10

5

0 Basketball Cricket Football Volleyball

a. Which is the most popular game in the class?

b. Which is the least popular game in the class?
c. How many students like basketball?

d. How many more students like football than cricket?
e. How many students are there altogether in class IV?

2. Given Bar graph represents favourite subjects of students of class IV. Read
this bar graph carefully and answer the questions given below:

40

35

30

25

20

15

10

5

0 English Nepali Maths Science Social Studies

a. Which is the most favourite subject?
b. Which is the least favourite subject?
c. How many students' favourite subject is Nepali?
d. How many more students' favourite subject is Nepali than Maths?

Oasis School Mathematics Book-4 233

3. Marks obtained by Paribesh in an examination in different subjects are given
below. Draw the bar graph to represent this information.

Subjects : English Nepali Maths Science Social Studies
Marks :
35 32 28 40 30

4. The given table shows the number of different types of fruits in a fruit shop.
Draw the bar graph to represent this information.

Fruits : Mango Orange Apple Banana Pomegranate

Number : 15 25 30 35 10

Answer: Consult your teacher.

Billing

When we go to a shop to buy something, the shopkeeper gives a bill. On the
bill there is detail about the quantity and price of the things that we buy.

Look at the given bill and learn how to prepare it.

Oasis PAN No.

Kastup Shah

Oasis School Mathematics Book IV
Oasis School Science Book IV

Remember ! • rate of each item
A bill has • total cost of all items
• name and address of shop or store • signature of salesman
• bill number
• PAN • quantity of each item
• date of issue of the bill

234 Oasis School Mathematics Book-4

Class Assignment

Aadhya purchased the following items from Sijan Store.
Prepare a bill given to her by the shopkeeper.

Rs. 75 Rs. 35 Rs. 60 Rs. 80 Rs. 120

Sijan ColdStore Chabahil

Kathmandu

Pan No: .............

Bill No. 226
Mr/Mrs/Ms ........................... Date .....................

S.N Description Quantity Rate Amount

1.

2.

3

4.

5.

Total

...........................
Salesman

Price list of Jimmy Store Kathmandu is given below:

Price list

Mansuli rice Rs 60 per kg

Basmati rice Rs. 90 per kg

Sugar Rs. 85 per kg

Tea Rs. 350 per kg

Dal Rs. 180 per kg

Ranjita bought 3 kg Mansuli rice, 2 kg Basmati rice, 1 kg tea, 2 kg sugar and 1
kg pulse. Prepare the bill.

Oasis School Mathematics Book-4 235

Jimmy Store

Kathmandu

PAN No: .............

Bill No. 226
Mr/Mrs/Ms ........................... Date .....................

S.N Description Quantity Rate Amount

1.
2.
3
4.
5.

Total

...........................
Salesman

Exercise 11.2

1. Aarya purchased the following items from Akriti Stationery Sukedhara,
Kathmandu. Prepare a bill given to her by the shopkeeper.

Rs 15 Rs 25 Rs 5 Rs 50

2. Sundar bought the following items from Khanal Store, Biratnagar. Prepare a
bill for the following items.
a. 5 kg of rice at a rate Rs. 55 per kg

b. 2 kg of sugar at a rate of Rs 65 per kg

c. 3 kg of tea at the a of Rs 220 per kg

d. 1 litre sunflower oil at a rate of Rs 120 per litre

236 Oasis School Mathematics Book-4

3. Zenith, Himanka and Sankalpa went to Kids Fun Corner.
• Zenith ordered one plate of vegetable MoMo and a cup of coffee.

• Himanka ordered one plate of chicken MoMo and a cup of tea.

• Sankalpa ordered one full Tandoori chicken.

Prepare a bill. Kids Fun Corner

Vegetable MoMo Rs 50 per plate

Chicken MoMo Rs 90 per plate

Tea Rs 10

Coffee Rs 20

Full Tandoori chicken Rs 450

4. Price list of Manish Store Butwal is given below:
Price list

Dal Rs 150 per kg

Potato Rs. 30 per kg Sukhilal bought
Tomato Rs. 60 per kg 5 kg Dal, 2 kg Potato,
Basmati rice Rs. 120 per kg

Sugar Rs. 90 per kg 3 kg Tomato, 1 kg Basmati rice and 5

Beaten rice Rs. 110 per kg kg Sugar. Prepare a bill.

Answer: Consult your teacher.

Temperature

Temperature means hotness or coldness of an object. The degree of hotness or
coldness of an object is expressed by its temperature.

The instrument used to measure the temperature is thermometer.

Temperature is measured in degree Celsius or in degree Fahrenheit.
This is a thermometer with Celsius scale. Its reading is 30° Celsius.

This is a thermometer with Fahrenheit scale. Its reading is 95°F.

30oc 30 degree Celsius
95oF 95 degree Fahrenheit

Oasis School Mathematics Book-4 237

Exercise 11.3

1. Write down the temperatures shown by the following thermometers in

Celsius scale:

a. c c. c

b. c
c d.

e. c f. c

2. Write down the temperatures shown by the following thermometers in

Fahrenheit scale: b.
a.

FF

c. d.

FF

e. f.

FF

3. Use a thermometer of Fahrenheit scale to measure:
a. Your temperature b. Temperature of your best friend

4. Make a list of maximum and minimum temperature of Kathmandu,
Pokhara, Biratnagar and Nepalugunj from a daily magazine and newspaper
the following questions:
a. Which place has the lowest temperature?

b. Which place has the maximum temperature?

c. Which city is the warmest? d. Which city is the coldest?

e. What is the minimum temperature of Kathmandu?

Answer: Consult your teacher. Activity Take a Celsius scale thermometer and record the temperature

of 9 A.M., 10 A.M., 11 A.M., 12 noon, 1 P.M., 2 P.M. and 3 P.M.

238 Oasis School Mathematics Book-4

Sets

The meaning of set is a ‘group’ or an ‘aggregate’. We can say that a collection
of objects is a set. A collection of books, a collection of a flowers, a collection of
even numbers etc. are called sets.

It is a set of flowers. It is a set of fruits. It is a set of wild animals.

In each collection, there are objects of the same nature.
Hence the set is “collection of well defined objects.” The objects of the set are
called its members or elements.
Example :

Cross the odd ones and name the set.
Here, 3, 5, 7 and 9 are the odd numbers and 8 is an

even number.
\ 8 is the odd one out.
It is 'a set of odd numbers'.

Remember !

The word intelligent, good, honest are not well defined. Collection of honest
people is not a set

Class Assignment

Tick (√) the collections which are sets and cross (X) the collections which are not sets.
a. Collection of birds
b. Collection of intelligent students
c. Collection of honest people of Nepal
d. Collection of even numbers from 1 to 10
e. Collection of vowel alphabets
f. Collection of planets
g. Collection of good football players

Oasis School Mathematics Book-4 239

Representation of sets

The sets are generally denoted by capital letters A, B, C, D,...... Its elements
are denoted by small letters a, b, c, d, ........ .
A set can be represented by pictures of its objects in a circle, rectangle,
square, etc.

A set of birds

Sometimes, it is difficult to show the sets in pictures. Therefore, other methods
of representing sets are:

a. Listing method (tabulation method)

b. Description method

Listing method (tabulation method)

In this method, all the elements of a set are listed within curly braces { },
separating each element by commas.

A = {mango, apple, orange, banana} A set of fruits

Description method

In this method, we describe the type of members of the set by descriptive
phrases.

For example: A set of even numbers less than 10

Listing Method Description Method

240 Oasis School Mathematics Book-4

Members of a set c.

Let, A = { a, b, c, d, e}
It is a set of first five English letters.
Here, ‘a’ is a member of A.
\ a belongs to A
It is denoted as a ∈ A
f is not a member of A.
\ f does not belong to A
It is denoted as f ∉ A

∈ belongs to
∉ does not belong to

Exercise 11.4

1. Cross the odd one out and name the set:
a. b.

a b e

i o u

2. List the elements of the following sets within brackets { } using listing
method:
a. The set of first four days of the week
b. The set of first three English months
c. The set of even numbers from 10 to 20
d. The set of any three domestic animals
e. The set of any three flowers

Oasis School Mathematics Book-4 241

2. Rewrite the following sets by description method:
a. {Baisakh, Jestha, Ashad, Shrawan}
b. {cauliflower, potato, tomato, garlic}
c. { a, e, i, o, u}
d. {11, 13, 15, 17, 19}

3. Rewrite the given sets in description as well as listing method:
a. b.

c. d.

4. Write ∈ or ∉ in the blanks. c___A, d___A e___A
a. A = {a, e, i, o, u}

a___A, b___A,

b. B = {10, 20, 30, 40, 50}

10___B, 20___B, 30___B, 40___B, 50___B

c. C = {mobile, laptop, i-phone, tablet}

mobile___C, Cow___C, laptop___C

Consult your teacher.

242 Oasis School Mathematics Book-4

Objective Questions

Colour the correct alternatives.
1. A set is the

Collection of Collection of Collection of
objects well defined objects in the
surroundings
2. Notation ∈ means objects

belongs to does not does not lie
belong to on

3. If A = {Lily, Marigold, Hibiscus, Rose}, then which of the following is correct
one

Lily ∈ A A ∈ Merigold Rose ∉ A

4.

42°F 40°C 42°C

5. 95°C 80°C
100°F

Number of correct answers

Oasis School Mathematics Book-4 243

Unit Test Full marks -20

1. Marks obtained by Suntali in different subjects are given below. Represent

this information in a bar graph. 5

Subjects English Nepali Science Maths Social Studies
35 30 35 25
Marks 40

2. Price list of different items in ABC Store is given below: 4

Sugar : Rs 80 per kg

Mansuli Rice : Rs 75 per kg

Pokhareli Rice : Rs 95 per kg

Dal : Rs 250 per kg

3. Write the reading of given thermometers. 3

4. List the following sets within the brackets. 3
a. The set of the first 3 days of week
b. The set of the first 3 months of Nepali year
c. The set of vowel letters

244 Oasis School Mathematics Book-4

UNIT

12 Algebra

12 Estimated Teaching Hours: 15
93

6

Contents • Literal numbers

• Constant and variables

• Translation of words into algebraic
expression

• Types of algebraic expression

• Factors and co-efficients

• Like and unlike terms

• Addition and subtraction of like and unlike
terms

• Addition and subtraction of algebraic
expressions

• Algebraic equation and its solution

Expected Learning Outcomes

Upon completion of the unit, students will be
able to develop the following competencies:

• To know the use of literal numbers
• To identify the constant and variable elements
• To translate the words into algebraic expression
• To know the types of algebraic expression
• To know the factors and co-efficients
• To distinguish like and unlike terms
• To add and subtract the like terms
• To add algebraic expressions
• To convert mathematical sentence into algebraic expression

and solve them

Materials Required: Play cards, list of formula, glue, scissors, etc.

Oasis School Mathematics Book-4 245

Introduction
Literal numbers

Algebra is another form of arithmetic. In algebra, we use letters to represent
numbers. The numbers may be expressed by 0, 1, 2, 3, ..... 9 or by means of a,
b, c, d, .......x, y, z. The digits 0, 1, 2, 3, 4, .... 9 have their fixed values. But the
letters a, b, c, d, .....x, y, z do not have their fixed values. These letters are called
literal numbers.

I understand, letters are used to
represent numbers.

There are x pencils. x=5
The value of x is 5.
Literal number Constant

Signs used in literal numbers
If ‘x’ and ‘y’ are literal numbers, the sum of x and y is denoted by (x + y).

Product of x and y is denoted by x × y or xy.

Difference of x and y is denoted by x - y.

Quotient of x and y is denoted x ÷ y or x .
y

Constant and variables

Constant

1, 2, 3, 4 ,5, 6 ,... etc have fixed numerical values. Such numbers are called
constants. For example, the number of sides of a quadrilateral is 4. It is a
constant.
Variables

The letters a, b, c, d, .... x, y, z, are used to represent different numbers.
They do not have their fixed values. These letters are called variables. For
example, temperature of Kathmandu is not fixed, its value changes. Therefore,
temperature of Kathmandu is a variable.

246 Oasis School Mathematics Book-4

Exercise 12.1

1. Determine whether the following statements represent variables or constants.
a. The number of sides of a triangle
b. The letters of the word MATHEMATICS
c. The number of even numbers from 1 to 20
d. The temperature of Kathmandu.
e. The number of students in a school
f. The odd numbers from 1 to 30

2. Fill in the blanks.
a. ‘x’ represents the number of odd numbers from a 1 to 50. Then ‘x’ is a
.........................
b. ‘y’ represents the number of sides of a quadrilateral. Then ‘y’ is a
.........................
c. ‘z’ represents the number of animals in a zoo. Then ‘z’ is
a.........................
d. 'w' represents the number of fingers of human body. Then w is a
...................

Consult your teacher.

Algebraic Expression

Let's take x + 5 where x is a literal number (3x + 7y) expression
and 5 is a constant which are connected by
arithmetic operation '+'. x + 5 is an algebraic term term
expression. x and 5 are its terms.

Hence, an expression made up of literal numbers and constant connected by arithmetic
operation is called an algebraic expression.

Translation of words into algebraic expression

The sum of x and 3 is denoted by (x + 3).

The difference of z and 5 is denoted by (z - 5).

The product of y and 7 is denoted by 7y. m9 .

The quotient of 9 and m is denoted by 9 ÷ m, or
All these are algebraic expressions.

An algebraic expression has one or more than one terms.

The terms of expressions are separated by ‘+’, ‘-’ sign.

Oasis School Mathematics Book-4 247

Conversion of statement related to addition into algebraic
expression

Statement Algebraic expression I have to use the ‘+’ sign in
The sum of x and 7 x+7 condition of ‘sum’ ‘is added
5 is added to x x+5 to’ ‘is increased by’ and ‘more
y is increased by 2 y+2
10 more than z z + 10 than’.

Conversion of statement related to subtraction into algebraic expression

Statement Algebraic In case of difference, subtracted
expression from, decreased by, is less than, I
The difference of x and 5
2 is subtracted from z x-5 have to use ‘-’ sign.
y is decreased by 7 z-2
4 less than m y -7
m -4

Conversion of statement related to multiplication
into algebraic expression

Statement Algebraic 4x = 4 × x
expression
x is multiplied by 4 In case of product, times, is
5 times y 4x multiplied by, I have to use
The product of 7 and z 5y
7z ‘×’ sign.

Conversion of statement related to division into
algebraic expression

Statement Algebraic ÷ sign is used in the statement ‘divided
expression by’ and ‘quotient of’.
x is divided by 2
The quotient of y and z (x ÷ 2)

(y ÷ z)

248 Oasis School Mathematics Book-4

Conversion of statement related to two or more operations

Statement Algebraic expression
The product of 5 and x is increased by 7 (5x + 7)
10 is subtracted from the product of 3 and x (3x – 10)
Two times y is added to three times x. 3x + 2y

Product of 5 and x = 5x
Increased by 7 = 5x + 7

Exercise 12.2

1. Write the terms of the following expressions.
a. 2x + 3y b. 5x - y c. 4x + y - 7 d. 6x - 2y + 9 e. 2a - 5b + 3c

2. Represent the following statements in algebraic expression.

a. x is added to y b. a is added to 7

c. 7 is subtracted from y d. n is decreased by 8

e. 5 is multiplied by x f. p is decreased by q

g. 7 times n

h. p is divided by q

i. the quotient of m and n

j. 2 times the x is added to y

k. three times the z is added to 2 times the y

l. 3 times m is decreased by 8

m. the sum of four times x and three times y

n. 5 is subtracted from 6 times of y

o. 3 times y is subtracted from 2 times x

3. Write each of the following algebraic expressions in word.

a. 5x b. 2x + 1 c. 3x + y d. 6m + 2x

e. p f. 3z - 4 g. 4x h. 5x - 3y
q 3y

Oasis School Mathematics Book-4 249

4. Write the algebraic expression for each of the following.
a. Aaradhya had Rs x. Her mother gave her Rs 10. How much money
does she have now?
b. Anjali had Rs 20. She spent Rs x. How much money is left?
c. Dipsha is x years old. What will be her age after 3 years?
d. The cost of one copy is Rs x. What is the cost of 6 such copies?
e. The cost of a pen is Rs y. What is the cost of 10 such pens?

5. Take a number x and perform the following operation to get algebraic
expression.
a. 5 times the number is added to 7.
b. 3 times the number is added to 1.
c. 1 is subtracted from two times the number.
d. 5 is subtracted from three times the number.
e. 9 is added to three times the number.

Consult your teacher.

Types of algebraic expressions

The algebraic expressions may contain one, two, three or more than three terms.
Depending upon the number of terms, the algebraic expressions are classified as
follows:
Monomial
If an algebraic expression contains only one term, then it is called a
monomial.

Example :

5x, 2y, 3z, etc. are monomials.
Binomial
If an expression contains two terms, then it is called a binomial.
2x + 5y, 3y - 7z, etc. are binomials.

Trinomial
If an expression contains three terms, then it is called a trinomial.

3x is a monomial
5x + 3 is a binomial.
a + 3b - 2c is a trinomial

250 Oasis School Mathematics Book-4