4. 5 units = $485 - $10 - $10 - $10 - $10 = $485 - $40 = $445 I unit = $445 ÷ 5 = $89 $89 + $10 = $99 Ans: $99 5. 6. Cost of microwave oven = $1358 - $379.50 = $978.50 Cost of both machines = $978.50 + $1358 = $2336.50 Mrs Menon’s amount= $2336.50 - $370 = $1966.50 Ans: $1966.50 Robert Siblings 10 10 10 10 $485 34 34 15 $293 Susan Jean Carly 3 units = $293 - $34 - $34 - $15 = $210 1 unit = $70 Susan’s amount = $70 + $34 = $104 Ans: $104 Washing machine Microwave oven $1358 $379.50 ? 101 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
7. Working Backwards Method Amount of money Mr Soo had at first = $272 + $ 478.75 + $1 590.50 - $500 = $1841.25 Ans: $1841.25 8. Working Backwards Method Amount of money Mrs Wong had at first = $28.20+ $25.90 + $88.50 - $25 = $117.60 Ans: $117.60 9. Value of 5 fifty-dollarnotes = 5 x $5 = $25 $1 → 2 fifty-cent coins $25 → 25 x 2 = 50 fifty-cent coins Ans: 50 fifty-cent coins 10. Value of 2 ten-dollar notes = 2 x $10 = $20 Value of 3 five-dollar notes = 3 x $5 = $15 Value of 20¢ received = $20 - $15 = $5 $1 → 5 twenty-cent coins $5 → 5 x 5 = 25 twenty-cent coins Ans: 25 twenty-cent coins 11. 3 slices of cake = 3 x $1.50 = $4.50 One slice of cake is given away free with purchase of 3 slices. $4.50 → 4 slices $9.00 → 8 slices $18 00 → 8 x 2 = 16 slices Ans: 16 slices of cake 102 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
12. 3 smart phones = 3 x $490 = $1470 4th smart phone = $490 ÷ 2 = $245 4 smart phones = $1470 + $245 = $1715 12 smart phones = 3 x $1715 = $5145 Ans: $5145 13. Since there is an equal number of diaries and bookmarks, $5 + $2 = $7 Number of bookmarks= 399 ÷ 7 = 57 Ans: 57 bookmarks 14. Since there is an equal number of hand creams and hand sanitizers, $2 + $6 = $8 Number of bottles of hand sanitizers = 128 ÷ 8 = 16 Ans: 16 bottlesof hand sanitizers 103 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
Boost! Math Primary 3 Lesson 32:Length Answer Key 1. a) 1 km 152m b) 15 km 678 m c) 28 km 924 m d) 67 km 1 m 2. a) 1 087m b) 10 020 m c) 25 505 m d) 88 001 m 3. 12 598 m, 12 km 75 m, 1 km 275 m, 598 m 4. 435 m, 1050 m, 1 km 55 m, 10 km 5m 5. 15 004 m 6. 25 110 m 7a. 1 km 450 m = 1450 m 5 days → 5 x 1450 = 7250m 7b. 1450 x 2 = 2900 2900 x 2 = 5800 7250 + 5800 = 13 050 Ans: (a) 7250 m (b) 13 050 m or 13 km 50 m 8a. Distance of longer route → 580 + 60 = 640 m Distance covered in one day → 580 + 640 = 1220 m 8b. Total distance covered in 5 days → 5 x 1 220 = 6100 m (a) Ans: 1220 m or 1 km 220 m (b) Ans: 6100 m or 6 km 100 m 104 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
9. 11a. 11b. 2 m = 200 cm Length of raffia needed for 3 boxes → 3 x 45 = 135 cm Length of raffia left → 200 – 135 = 65 cm Length of raffia used for 4 parcels → 65 – 17 = 50 cm Length of raffia used for 1 parcel → 48 ÷ 4 = 12 cm Ans: (a) 65 cm (b) 12 cm B C 30 20 200 30 A ? 3 units = 200 – 30 – 30 – 20 = 200 – 80 = 120 cm 1 unit = 120 ÷ 3 = 40 cm Length of A → 40 + 30 + 20 = 90 cm Ans: 90 cm 10. A + B =151 cm → (1) B + C = 147 cm → (2) A + C = 130 cm → (3) (1) + (2) + (3): 2A + 2B + 2C = 151 + 147 + 130 = 428 cm A + B + C = 428 ÷ 2 = 214 cm → (4) To find the value of A, we take (4) – (2) A = 214 – 147 = 67 cm Ans: 67 cm 105 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
12. Total height last year → 282 – 8 – 5 = 269 cm R T 2 units = 269 – 5 = 264cm 1 unit = 264 ÷ 2 = 132cm Ans: 132 cm 13.Interval length → 135 cm Number of intervals → 9 –1 = 8 Length of room → 8 x 135 = 1080cm = 10 m 80 cm Ans: 10 m 80 cm 14. Number of intervals → 12 – 1 = 11 Length of durian plantation → 12 x 11 = 121 m Ans: 121 m 15.Number of intervals from 1st to 11th lamp post → 11 – 1 = 10 Total distance of 10 intervals → 10 x 35 m = 350 m 2 min = 350 m Another 4 min → 2 x 350 m = 700 m Total distance → 350 + 700 m = 1050 m = 1 km 50 m Ans: 1 km 50 m 269 5 106 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
5 units = 128 kg + 12 kg = 140 kg I unit = 140 kg ÷ 5 = 28 kg 2 units = 2 x 28 kg = 56 kg Gwen’s mass → 56 kg – 12 kg = 44 kg Ans: 44 kg Boost! Math Primary 3 Lesson 33: Mass Answer Key 1a. We assume that all the containers that Mr Chan packed were small containers. Mass of 9 small containersof sugar → 9 x 480 = 4320g Differencein mass from the actual mass of the sugar → 8 kg 320 g – 4320 g = 8320 g – 4320 g = 4000 g Mass of each large container more than each small containerof sugar is 1000 g. Number of large containers of sugar Mr Chan packed → 4000 ÷ 000 = 4 1b. 9 – 4 = 5 Ans: (a) (b) 4 large containers (b) 5 small containers. 2a. Mass of ginger Mrs Ghosh packed → 10 kg – 450 g = 10 000 g – 450 g = 9550g We assume that all the bags of ginger she packed were small bags. Mass of 7 small bags of ginger → 7 x 650 g = 4550 g Differencein mass from the actual mass of ginger packed → 9550 g – 4550 g = 5000 g Diff in mass between 1 large bag and 1 small bag of ginger → 1 kg 650 g – 650 g = 1650 g – 650 g = 1000 g Number of large bags of ginger she packed → 5 000 ÷ 1000 = 5 2b. 7 – 5 = 2 Ans (a) 5 large bags of ginger (b) 2 small bags ginger 3. Winnie Gwen Tessa 12 kg 128 kg ? 107 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
9 units = 855 g I unit = 855 g ÷ 9 = 95 g 2 units = 2 x 95 g = 190 g Ans: 190 g 7b. Heaviest person → Gordon = 43 kg 065 g = 43 605 g Lightest person → Eric = 35 kg 22g = 35 022 g Difference in mass between the heaviest and the lightest person → 43 605 – 35 022 = 8 583 Ans: (a) 35 kg 22 g / 35 022 g. (b) 8583 g 4. 5. 5340 g 1 unit = 890 g 6 units = 6 x 890 g = 5340 g = 5 kg 340 g Ans: 5 kg 340 g or 6a. Mass of Present C → 94 kg ÷ 2 = 47 Mass of PresentB → 96 kg - 47 = 49 kg Mass of PresentA → 82 kg – 49 kg = 33 kg 6b. Mass of Present D → 2 x 47 kg = 94 kg Heaviest presentis Present D. Lightest present is Present A. Difference in mass between PresentD and PresentA → 94 kg – 33 kg = 61 kg Ans: 61 kg 7a. Gordon → 43 kg 605 g = 43 605 g Frank → 43 605 g – 3825 g = 39 780 g Darren → 39 780 g + 2500 g = 42 280 g Eric → 42 280 g – 7258 g = 35 022 g = 35 kg 22 g BagB Bag C BagA 855 ? Tin A Tin B Before 890 ? Tin A Tin B After received gave 108 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
8. 9. We assume that all the sacks of sunflower seeds were small sacks. Mass of 12 small sacks of sunflower seeds → 12 x 5 kg = 60 kg Difference in mass from the actual mass of all the bags of sunflower seeds bought → 75 kg - 60 kg = 15 kg Mass of 1 big sack of sunflower seeds → 2 x 5 kg = 10 kg Difference in mass between 1 small bag and 1 large bag →10 kg – 5 kg = 5 kg Number of large sacks of sunflower seeds bought → 15 ÷ 5 = 3 Number of small sacks of sunflower seeds bought→ 12 – 3 = 9 Differencein number of small sacks than large sacks bought→ 9 – 3 = 6 Ans: 6 more small sacks 10. 1 unit 1 unit 1 unit 2 B A 130 kg ? 3 units = 130 kg – 29 kg – 29 kg = 72 kg 1 unit = 72 kg ÷ 3 = 24 kg 2 units = 2 x 24 kg = 48 kg Ans: 48 kg 2 940 g A 1 unit B 4 units = 940 g 1 unit = 940 g ÷ 4 = 235 g 3 units (B before the transfer)→ 3 x 235 g = 705 g Amount of pancake mix in Bag B aftertransfer→ 705 g – 180g = 525 g Ans: 525 g 1 unit 1 unit 1 unit 109 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
11a. Mass of Vase D → 29 kg Mass of Vase C → 2 x 29 kg = 58 kg Mass of Vase B → 95 kg – 58 kg = 37 kg Mass of Vase A → 98 kg – 37 kg = 61 kg 11b. Total mass of all four vases → 61 kg + 37 kg + 58 kg + 29 kg = 185 kg Ans: (a) 61 kg (b) 185 kg 12. Nelson → 2650 kg Mark → 3850 kg – 2650 kg = 1200 kg Liam → 1200 kg - 804 kg = 396 kg Jake → 396 kg ÷ 2 = 198 kg (a) Jake has harvested 198 kg of beans. Total amount of beans harvested → 198 kg + 396 kg + 1200 kg + 2650 kg = 4444 kg Ans: (a) 198 kg (b) 4444 kg. 110 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
Boost! Math Primary 3 Lesson 34:Volume Answer Key 1. 1500 ml - 650 ml = 850ml Ans: 850 ml 2. 4 ℓ = 4 000ml 2 ℓ 275 ml = 2275 ml Amount of rose syrup = 4000 ml - 2275 ml = 1725 ml more = 2275 ml - 1725 ml = 550 ml Ans: 550 ml 3. 350 ℓ - 190 ℓ = 160 ℓ (tofill) 160 ÷ 8 = 20 Ans: 20 times 4. 1 unit = 22ℓ 6 units = 132 ℓ Ans: 132 ℓ 5. 4 200 ml - 300 ml = 3 900ml 3 900 ÷ 5 = 780 ml Ans: 780 ml 6. Beaker X = 3 ℓ 200 ml = 3200 ml Beaker Y = 1 ℓ 600 ml = 1600 ml 3200 ml - 1600 ml = 1600 ml 1600 ÷ 2 = 800 ml Ans: 800 ml 7. 5 units = 750 ml 1 unit = 750 ÷ 5 = 150 ml 3 units = 3 x 150 = 450 ml Ans: 450 ml 111 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
8. ContainerY = 300 ml Container Z = 150 ml Final reading on Container Z = 300 ml Amount of coloured Container Z needs = 300 ml - 150 ml = 150 ml Volume of coloured water left in Container Y = 300 ml - 150 ml = 150 ml Ans: 150 ml 1 unit 9. Bottle A 320 ml Bottle B ? 580 ml 2 units = 320 ml + 580 ml = 900 ml (total) 1 unit = 900 ÷ 2 = 450 ml (each bottle in the end) 580 ml – 450 ml = 130 ml (poured) Ans: 130 ml 10. 8 cups of water = 280 x 8 = 2240 ml Water at first = 4275 – 2240 = 2035 ml 2035 ml = 2 ℓ 35 ml Ans: 2 ℓ 35 ml Method 2 More = 580 -320 = 260 ml Pour = 260 ÷ 2 = 130 ml 112 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
11. The difference in volume is the volume of the additional juice. 6 ℓ 360 ml et of juice 5 ℓ 400 ml Volume of 2 packets of juice = 6 ℓ 360 ml - 5 ℓ 400 ml = 960 ml 960 ÷ 2 = 480 ml Ans: 480 ml 12. 2 units = 350 ml 1 unit = 350 ÷ 2 = 175 ml 3 units = 3 x 175 ml = 525 ml Ans: 525 ml 2 packets of protein shake 1 pack 2 packets of protein shake Before: Jug Y Jug Z After: Jug Y Jug Z 1 unit 350ml 13. Supposition Method:Assume that all were small bottles of green tea. Total volume of 11 small bottles = 11 x 2 = 22 ℓ Difference in volume from the actual volume of green tea Gabrielle used = 46 ℓ - 22 ℓ = 24 ℓ Difference in volume between each big bottle than each small bottle = 5 ℓ - 2 ℓ = 3 ℓ Number of big bottles of green tea = 24 ÷ 3 = 8 Number of small bottles of green tea = 11 ℓ - 8 ℓ = 3 ℓ 8 – 3 = 5 OR use Guess and Check Table Ans: (a) 8 big bottles (b) 5 more big than small bottles of green tea 113 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
Number of Minutes Monday Tuesday Wednesday Days of a Week Thursday Friday 60 50 40 30 20 10 1. The table below shows the time Michel spent exercising each weekday in a week. Complete the bar graph below to represent the data. 114 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed. Boost! Math Primary 3 Lesson 35: Bar Graph Answer Key
2. A school has 5 sports CCA clubs. The table below shows the number of members each club has. Complete the bar graph below to represent the data. Names of CCAClubs Number of Members Baseball Basketball Volleyball Soccer Hockey CCA Club Number of Members Baseball 45 Basketball 60 Volleyball 35 Soccer 30 Hockey 40 CCA Sports Clubs 60 55 50 45 40 35 30 25 20 15 10 0 115 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
3. A football club had to vote to choose the colour of a new mascot. The votes are shown in the table below. Complete the bar graph to represent the data. Be sure to include a scale and labels on both axes. Colour Number ofVotes Red 16 Green 18 Blue 14 Yellow 12 Pink 6 Purple 10 Votes for a New Mascot Number of Votes 20 18 16 14 12 10 8 6 4 2 0 Red Green Blue Yellow Colour Pink Purple 116 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
4. The bar chart below shows the favourite type of YouTube videos watched by some students. Create your own bar graph using the information provided. 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 Try Not to Laugh Pranks Gaming Tutorials Try Not to Laugh IIII IIII IIII IIII IIII IIII III Pranks IIII IIII IIII IIII IIII IIII Gaming IIII IIII IIII IIII IIII IIII IIII II Tutorials IIII IIII IIII IIII IIII I Favourite YouTube Videos Name of Video Number of Students (a) 125 students (b) Gaming (c) 29 – 26 = 3 Ans: 3 117 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
5. The table below shows the scores students received in a spelling test. Complete the bar graph below to represent the data. Name Score /30 Ricky 28 Lucy 24 Chan 20 Jed 26 Corey 20 Bevan 22 Score /30 Ricky Lucy Chan Jed Names of Students Corey Bevan 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 (a) Ricky and Jed (b) Chan (c) 26 – 22 = 4 (d) 30 – 20 = 10 (e) Chan and Corey 118 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
6. The graph below shows the number of app notifications 4 people receive in a week. Use the bar graph below to answer the questions that follow.. App Notifications in One Week Esther Francine Geronimo Henry = 4 notifications (a) Francine (b) 20 – 18 = 2 (c) 20 + 30 = 50 (d) Henry (e)Geronimo (f) 30 – 18 = 12 (g) Francine and Henry (h) 24 – 20 = 4 119 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
7. The bar graph below shows the amount of time some students spend in studying on a weekend. Use the plot graph below to answer the questions that follow. Time Spent on Studying on a Weekend = 2 students 2.5 h 3 h 3.5 h 4 h 4.5 h 5 h 5.5 h Time Spent Studying (a) 55 (b) 5.5 h (c) 15 – 10 = 5 (d) 14 – 2 = 12 (e) 14 – 2 = 12 120 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
8. The bar graph below shows the favourite board games of the entire P3 level of Pal Primary School. Use the bar graph to answer the questions below. Favourite Board Games – Primary 3 Level 68 66 64 62 60 58 56 54 52 50 48 46 44 42 40 38 Checkers Chess Cluedo Monopoly Number of Students 121 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed. Name of Board Game (a) 57 + 63 + 68 + 61 = 249 (b) Checkers (c) Chess (d) 68 – 61 = 7 (e) 68 – 57 = 11
9. Mr Chua owns a café. The graph below shows the number of various pies he sold in a week. Use the graph to answer the questions that follow. Pieces of Pie Sold 70 60 50 40 30 20 10 0 Apple Pumpkin Pecan Blueberry Number of Pies Sold Peach Cherry Type of Pie (a) 50 – 20 = 30 (b) Pumpkin pies (c)Cherry and Pecan pies (d) 3 x 20 = 60 Ans: Blueberry pie (e) 30 x $3 = $90 122 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
10. The graph below shows the amount of time Janelle spent practicing the violin each day of the week. Then answer the questions that follow. Amount of Time Janelle Practises Violin Per Day 60 50 40 30 20 10 0 Mon Tue Wed Thur Fri Sat Time Spent (min) Sun Days of the Week (a) 35 + 50 = 85 min (b) 50 – 20 = 30 min (c) 60 – 30 = 30 min (d) 55 – 10 = 45 Ans: Tuesday (e) 35 + 20 = 55 min Ans: Monday and Thursday 123 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
Boost! Math Primary 3 Lesson 36: Sem 2 Review 1 Answer Key Section A (2 marks each) 1) 3 2) 3 3) 3 4) 2 5) 3 6) 1 7) 4 8) 2 9) 3 10) 3 Section B (2 marks each) 11. 1 250 g + 750 g = 2 000g 2 000 g = 2 kg Ans: 2 kg 12.5 000 g – 750 g = 4 250 g Ans: 4250 g 13.$7 - $3.90 = $3.10 2 x $3.10 = $6.20 Ans: $6.20 14. (a) 70 ÷ 2 =35 Ans: Peach (b) 25 + 15 = 40 Ans: Kiwi and Blueberry 15. 139 cm + 11 – 30 cm = 120cm Ans : 120 cm 16. 12 x 8 =96 96 + 13 = 109 Ans: 109 17. Pattern: +3 Pattern 4: 13 +3 Pattern 5: 16 +3 Pattern 6: 19 +3 Pattern 7: 22 Ans: 22 124 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
18. 15 cm – 3 cm = 12 cm 12 cm – 2 cm = 10 cm Ans: 10 cm 19. 308 – 172 =136 Y = 136 136 ÷ 4 = 34 X = 34 Ans: X = 34, Y = 136 20. $15 ÷ $4 = 3 R1 3 groups = 3 x 4 = 12 Ans: 12 oranges Section C: 21. (a) No of pupils who don’t eat any fruits = 6 No of pupils who eat 1 fruit = 11 No of pupils who eat less than 2 fruits = 6 + 11 = 17 Ans: 17 pupils (b) No of pupils who eat 3 fruits = 7 No of pupils who eat 4 fruits = 3 Total no of pupils = 6 + 11 + 7 + 3 = 27 Ans: 27 pupils 22. RouteA = 1 270 m + 2 160 m = 3 430 m Difference between Route A and B = 3 785 m – 3 430 m = 355 m Ans: 355 m 23. (a) RopeA Rope B 620 cm Rope C 80 cm 180 cm 125 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
3 units = 620 cm – 80 cm – 180 cm = 360 cm 1 unit = 360 cm ÷ 3 = 120 cm Rope C = 120 cm + 180 cm = 300 cm Ans: 300 cm or 3 m 24. (a) Alex = 3 units ($1 500) Zac = 1 unit 1 unit = $1 500 ÷ 3 = $500 Ans: $500 (b) Total amount the boys contributed = 2 x $50 = $100 Total amount the boys saved = $1 500 + $500 = $2 000 Total amount left = $2 000 - $100 = $1 900 Ans: $1900 25. (a) 3 ℓ = 3 000ml Total amount of lemonade in Jug A and B = 3 000 ml + 1 700 ml = 4 700 ml Ans: 4700 ml (b) In the end, each has half the total amount of lemonade = 4 700 ml ÷ 2 = 2 350 ml Amount of lemonade Jug B needs = 2 350 ml - 1 700 ml = 650 ml Ans: 650 ml 126 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
Boost! Math Primary 3 Lesson 37: Fractions 1 Answer Key 1. For questions (a) to (h), pupils are to shade the correct number of parts as stated by the fractions given. 2. (a) 1 8 (b) 4 8 (c) 5 6 (d) 2 5 (e) 2 4 (f) 1 3 (g) 1 2 (h) 5 6 3. 4. 5. (a) True 1 4 8 = 2 (Multiply both numerator and denominator by 2.) (b) False 3 6 2 = 4 (Multiply both numerator and denominator by 2.) (c) True 8 10 5 = 4 (Divide both numerator and denominator by 2.) (a) 1 , 2 3 3 (b) Accept any plausible answers. e.g. 1 = 2 or 1 = 3 or 2 = 4 or 2 = 8 etc 3 6 3 9 3 6 3 12 (c) 1 , 2 , 3 , 4 , 5 , 6 7 7 7 7 7 7 (d) Accept any plausible answers. (e) 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 9 9 9 9 9 9 9 9 (f) Accept any plausible answers. (a) 6 , 8 9 12 (b) 6 , 9 14 21 (c) 2 , 3 8 12 (d) 4 , 6 10 15 (e) 8 , 12 12 18 127 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
6. For questions (a) to (f), accept all equivalent fractions of the fraction stated other than the suggested answers below. (a) 6 3 , 12 (b) 2 , 4 , 6 (c) 3 , 6 , 9 10 5 30 5 10 15 4 8 12 (d) 6 , 3 , 9 (e) 2 1 , 3 (f) 2 , 1 , 3 8 4 16 10 5 15 6 3 9 7. 8. Tutor to play the Quiz Slides. Listen carefully as your teacher reads out the quiz questions. Write your answers in the boxes on page 8 of your worksheets. (a) 2 6 (b) 4 5 (c) 1 , 14 3 42 (d) True (e) False (f) 3 parts (g) 1 8 (h) 5 6 (i) 4 10 , 6 (Accept all equivalent fractions of 2 .) 15 5 Top Row (Left to Right) MiddleRow (Left to Right) Bottom Row (Left to Right) 1 , 2 , 2 , 1 , 1 1 , 2 , 1 , 1 , 1 1 , 1 , 1 , 1 , 11 2 7 3 16 8 6 5 10 14 4 4 13 9 12 12 Note: Both 4 16 P and 2 8 = 1 . 4 Remind pupils to look carefully before writing L their answers in the blanks. Answer to Riddle: He had too many problems. 128 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
Boost! Math Primary 3 Lesson 38: Fractions 2 Answer Key 1. (a) The number line has 5 parts. List the fractions. 5 5 5 5 0, 1 , 2 , 3 , 4 , 1 Ans: 2 , 4 5 5 (b) The number line has 10 parts. List the fractions. 0, 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 1 10 10 10 10 10 10 10 10 10 8 = 4 10 5 Ans: 3 , 4 10 5 (c) The line has 6 parts. 6 6 After listing, we have 3 and 5 respectively. 3 = 1 6 2 Ans: 1 and 5 2 6 (d) The line has 8 parts. 8 8 After listing, we have 2 and 4 respectively. Simplify fractions where possible. Ans: 1 and 1 4 2 (e) 2 X 3 = 6 7 3 21 The pattern of numerators is 2, 4, 6, 8, 10, 12. 21 12 The fractions are 8 and 21 respectively. Simplify fractions where possible. Ans: 8 and 4 21 7 129 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
( 15 ) 20 16 20 ( ) ( 8 ) ( 9 ) 12 12 18 20 (f) 1 X 9 = 9 2 9 18 The pattern of numerators is 1, 3, 5, 7, 9, 11. The fractions are 3 and 4 respectively. 18 7 Simplify where possible. Ans: 1 and 11 6 18 2. (a) 2 , 5 , 7 8 8 8 (b) 1 , 3 , 4 5 5 5 (c) 2 , 2 , 2 9 7 3 (d) 5 , 5 , 5 11 8 6 (e) Change to common denominator 20. , 7 20 3 , 4 4 5 (f) Change to common denominator 12. 5 12 , 2 , 3 3 4 3. (a) 5 , 3 , 2 7 7 7 (b) 9 , 7 , 3 10 10 10 (c) 3 , 3 , 3 8 9 11 (d) 7 , 7 , 7 8 9 11 6 (e) Change to common denominator 18. 5 , ( 15 ) 13 , 2 18 3 ( 12 ) 18 (f) Change to common denominator 20. ( 16) 17 , 4 , 3 20 5 4 ( 15 ) 20 4. (a) Simplify the fractions. = 2 1 3÷3 = 1 44 22 72 ÷3 24 The fractions are 1 22 23 , , 1 1 . 24 Ans: M = 23 (b) Simplify the fractions. = 4 ÷ 4 1 72 ÷ 4 18 3 ÷ 3 = 1 60 ÷ 3 20 The fractions are , 1 , 1 1 . 18 19 20 Ans: M = 19 5. (a) The lowest common multiple of 15, 12 and 20 is 60. 15 4 = 60 12 5 23 4 92 5 = 60 5 20 3 33 3 = 60 96 Z x 5 falls between 92 and 96. Z x 5 = 95 Ans: Z = 19 130 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
(b) The lowest common multiple of 2, 5 and 15 is 30. 3 15 45 5 6 6 = 2 15 = 30 15 2 = 30 30 6 28 2 56 The value of Z x 6 falls between 45 and 56. Z x 6 = 48 Z x 6 = 54 Z = 8 OR Z = 9 Ans: Z = 8 or 9 6. (a) greater (b) greater (c) greater (Change both denominators to 40.) (d) smaller (Change both denominators to 48.) (e) smaller (f) smaller (Change denominator to 6.) (g) smaller (Change denominator to 15.) (h) greater (Change denominator to 12.) (i) smaller (Change denominator to 9.) (j) greater (Change denominator to 20.) 7. (a) 6 = 3 16 8 Ans: (b) 10 = 5 16 8 Ans: 9. Fig (a) = 5 9 Fig (b) = 5 9 Fig (c) = 3 9 Fig (d) = 6 = 2 9 3 Ans: (d) 9. 8 = 2 12 3 10 = 2 15 3 16 = 2 24 3 18 = 2 27 3 21 = 7 33 11 Ans: (e) 10. 27 = 3 36 4 12 = 3 16 4 25 = 5 30 6 15 = 3 20 4 18 = 3 24 4 Ans: (c) 131 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
11. The common multiple is 8 Sub-divide each square into 2 equal parts. 2 ÷ 2 = 1 8 2 4 12. The common multiple is 3 x 5 = 15. Sub-divide each rectangle into 3 equal parts. ÷ 9 3 = 3 15 3 5 14. The common multiple is 4 x 6 = 24. Sub-divide each square into 4 equal parts. 3 x 6 = 18 4 6 24 132 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
Boost! Math Primary 3 Lesson 39: Fractions 3 Answer Key Exercise 1: 1. 4 7 2. 7 9 3. 3 =1 6 2 4. 6 =3 8 4 5. 5 = 1 5 6. 6 =2 9 3 7. 2 + 2 =4 6 6 6 = 2 3 8. 2 + 3 = 5 10 10 10 = 1 2 9. 2 + 1 =3 4 4 4 10. 2 + 3 =5 8 8 8 11. 3 + 2 =5 6 6 6 12. 4 + 3 = 7 12 12 12 Exercise 2: 1. 1 8 2. 4 7 3. 3 =1 6 2 4. 3 =1 9 3 5. 3 - 4 2 4 =1 4 6. 4 6 - 1 6 =3 6 = 1 2 7. 7 - 2 = 7 7 5 7 8. 7 −10 4 = 3 10 10 9. 5 - 1 = 4 10 10 10 = 2 5 10. 10 − 10 1 - 10 2 = 10 7 10 11. 9 12 - 2 12 = 7 12 12. 8 −12 3 12 = 5 12 Exercise 3: 3 + 2 = 5 10 10 10 = 1 2 10 - 5 = 5 10 10 10 = 1 2 → 1 + 1 12 6 = 1 + 2 12 12 = 3 12 → 12 – 3 12 12 = 9 12 = 3 4 1a. Fraction of pie eaten by Marc and Neil → 3 + 2 = 5 10 10 10 = 1 2 Ans: 1 2 1b. Fraction of pie eaten by Luke → 10 − 5 = 5 10 10 10 = 1 2 Ans: 1 2 2. Total fraction of grapefruit eaten by Jimin and Jung Kook 1 + 1 = 1 + 2 12 6 12 12 3 = 12 Fraction of grapefruit left 12 − 3 = 9 12 12 12 = 3 4 Ans: 3 4 133 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
→ 1 + 1 3 2 = 2 + 3 = 5 6 6 6 → 6 - 5 6 6 = 1 → 3 + 5 7 14 = 6 + 5 = 11 14 14 14 → 14 - 11 14 14 = 3 → 1 + 1 8 4 = 1 + 2 = 3 8 8 8 → 8 - 3 8 8 = 5 8 → 1 + 1 2 4 = 2 + 1 = 3 4 4 4 → 4 - 3 4 4 = 1 4 → 3 + 5 7 21 = 9 + 5 = 14 21 21 21 = 2 → 3 - 2 = 1 3 3 3 Julie wants to shade → 3 5 but the rectangle has 10 equal parts. So convert to denominator 10 → 3 = 6 means she needs to shade 6 5 10 equal parts She must shade another → 6 – 1 = 5 equal parts Mat ate → 8 12 Mary ate → 3 = 9 4 12 Mary ate more → 9 - 8 = 1 12 12 12 → 4 = 1 → 12 - 3 - 4 - 2 = 3 = 1 12 12 12 12 12 4 3a. Fraction of chocolate cake eaten 1 + 1 3 2 2 3 5 = + = 6 6 6 Ans: 5 6 b. Fraction of chocolate cake left 6 − 5 6 6 1 = 6 Ans: 1 6 4a. Fraction of butter given away and eaten 3 + 5 7 14 6 5 11 = + = 14 14 14 Ans: 11 14 b. Fraction of butter left 14 − 11 14 14 3 = 14 Ans: 3 14 5a. Fraction of stamps given away in total 1 + 1 8 4 1 2 3 = + = 8 8 8 Ans: 3 8 b. Fraction of stamps left8 − 3 8 8 5 = 8 Ans: 5 8 6a. Fraction of lemon tart eaten in total 1 + 1 2 4 2 1 3 = + = 4 4 4 Ans: 3 4 b. Fraction of lemon tart Bella kept for her parents 4 − 3 4 4 1 = 4 Ans: 1 4 7a. Fraction of toys Lucille give away 3 + 5 7 21 9 5 14 = + = 21 21 21 = 2 3 Ans: 2 3 b. Fraction of toys Lucille was left with 3 − 2 = 1 3 3 3 Ans: 1 3 8. Julie wants to shade 3 5 But the rectangle has 10 equal parts. So convert to denominator 10 3 = 6 means 5 10 she needs to shade 6 equal parts She must shade another6 – 1 = 5 equal parts Ans: 5 9. 12 - 2 - 7 12 12 12 = 3 12 = 1 4 Ans: 1 4 10. Mat ate 8 123 9 Mary ate =4 12 Mary ate more 9 − 8 = 1 12 12 12 Ans: Mary, 1 12 11a. Fraction of the bar of chocolate given to Ronald 4 = 1 12 3 Ans: 1 3 11b. Fraction of the bar of chocolate was left 12 − 3 − 4 − 2 = 3 = 1 12 12 12 12 12 4 Ans: 1 4 134 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
→ 60 = 1 180 3 → 180 - 30 - 60 180 180 180 = 90 = 1 → 12 = 1 48 4 → 10 - 1 - 1 10 5 10 = 10 - 2 - 1 = 7 10 10 10 10 → 11 - 2 - 1 12 3 6 = 11 - 8 - 2 12 12 12 = 1 12 → 8 - 1 - 1 8 2 4 = 8 - 4 - 2 8 8 8 = 2 12a. Fraction of money spent on shirt 60 = 1 180 3 Ans: 1 3 b. Fraction of money left180 − 30 − 60 180 180 180 90 1 = = 180 2 Ans: 1 2 13. 48 - 12 – 24 = 12 Fraction of figurines given to Vera 12 = 1 48 4 Ans: 1 4 14. Fraction of flour left 11 − 2 − 1 15. Fraction of seats occupied by girls 10 − 1 − 1 10 5 10 10 2 1 7 = − − = 10 10 10 10 Ans: 7 10 12 3 6 11 8 2 = − − 12 12 12 = 1 12 Ans: 1 kg 12 16. Fraction of white chocolate bar left 8 − 1 − 1 8 2 4 8 4 2 2 = − − = 8 8 8 8 = 1 4 Ans: 1 4 135 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed.
Boost! Math Primary 3 Lesson 40: Time 1 Answer Key 136 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed. 1a) 6.39 1b) 3.53 1c) 7.45 1d) 7.56 1e) 2.11 1f) 1.55 1g) 10.20 1h) 8.30 1i) 3.02 1j) 10.27 1k) 6.56 1l) 9.50 2. a) 45 minutes past 2 / 15 minutes to 3 b) 30 minutes past 8 / 30 minutes to 9 c) 55 minutes past 1 / 5 minutes to 2 d) 10 minutes past 7 / 50 minutes to 8 e) 28 minutes past 9 / 32 minutes to 10 f) 19 minutes past 6 / 41 minutes to 7 g) 30 minutes past 1 / 30 minutes to 2 h) 30 minutes past 5 / 30 minutes to 6 3 a) b) c) d) e) f) 4a) b) c) d) e) f)
137 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed. 5a) 195 min 5b) 263 min 5c) 550 min 5d) 517 min 5e) 888 min 5f) 134 min 5g) 924 min 5h) 619 min 6a) 59 min = 0 h 59 min 6b) 83 min = 1 h 23 min 1 h = 60 min 83 – 60 = 23 min 6c) 137 min = 2 h 17min 2 h = 2 x 60 = 120 min 137 – 120 = 17 min 6d) 254 min = 4 h 14 min 4 h = 4 x 60 = 240 min 254 -240 = 14 min 6e) 362 min = 6 h 2 min 6 h = 6 x 60 = 360 min 362 – 360 = 2 min 6f) 625 min = 10 h 25 min 10 h = 10 x 60 = 600 min 625 – 600 = 25 min 6g) 543 min = 9 h 3 min 9 h = 9 x 60 = 540 min 543 – 540 = 3 min 6h) 918 min = 15 h 18 min 15 h = 15 x 60 = 900 min 918 – 900 = 18 min 7a) 1 h = 60 min 2h = 120 min Ans: 120 min 7b) 1 h = 60 min 1h 45 min = 60 min + 45 min = 105 min Ans: 105 min 7c) 3 h = 3 x 60 min = 180 min 3 h 30 min = 180 min + 30 min = 210 min Ans: 210 min 7d) 4 h = 4 x 60 min = 240 min 4 h 15 min = 240 min + 15 min = 255 min Ans: 255 min 7e) 9 h = 9 x 60 min = 540 min 9 h 30 min = 540 min + 30 min = 570 min Ans: 570 min 8a) 3 h = 180 min 95 min = 180 min + 15 min = 3 h 15 min Ans: 3 h 15 min 8b) 10 h = 600 min 605 min = 600 min + 5 min = 10 h 5 min Ans: 10 h 5 min 8c) 4 h = 240 min 260 min = 240 min + 20 min = 4 h 20 min Ans: 4 h 20 min 8d) 2 h = 120 min 137 min = 120 min + 17 min = 2 h 17 min Ans: 2 h 17 min
138 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed. 9a) 9b 9c) 10 End Time : 10.05 a.m. 10b) End Time : 7.05 p.m. 10c) End Time : 5.09 a.m. 1 h 17 min 6.15 a.m. 7.15 a.m. 7.32 a.m. Duration: 1 h 17 min ) 1 h 25 min 17 min 9.35 p.m. 10.35 p.m. 11.00 p.m. 11.17 p.m. 25 min + 17 min = 42 min Duration 1 h 42 min 2 h 17 min 25 min 2.43 p.m. 4.43 p.m. 5.00 p.m. 5.25 p.m. 17 min + 25 min = 42 min Duration 2 h 42 min a) 3 h 45 min 5 min 6.15 a.m. 9.15 a.m. 10 a.m. 10.05 a.m. 2.35 p.m. 6.35 p.m. 7.00 p.m. 7.05 p.m. 4 h 25 min 5 min 11.50 p.m. 4.50 a.m. 5.00 a.m. 5.09 a.m. 5 h 10 min 9 min
139 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed. 11a) End Time : 2.15 p.m. 11b) End Time : 10.55 a.m. 11c) End Time : 10.55 p.m. 2.15 p.m. 5.15 p.m. 6.00 p.m. 6.05 p.m. 3 h 45 min 5 min 10.55 a.m. 12.55 p.m. 1.00 p.m. 1.25 p.m. 2 h 5 min 25 min 10.55 p.m. 4.55 a.m. 5.00 a.m. 5.50 a.m. 6 h 5 min 50 min
Boost! Math Primary 3 Lesson 41: Time 2 Answer Key 140 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed. Exercise 1: 1. 15 mins fast 2.05 Actual time 1.50 2. 25 mins slow 11.50 Actual time 12.15 3. 20 mins faster 5.10 p.m. Correct time 4.50 p.m. 4. supposed to meet 4.25 p.m. reached 45 mins earlier 3.40 p.m. 5. 45 min + 35 min = 80 min or 1 h 20 min 15 mins slow 6.40 p.m. Actual time 6.55 p.m. (End Time) Start Time from 6.55 p.m. goes back 1 h 5.55 p.m. 5.55 p.m. goes back 20 min 5.35 p.m. Exercise 2: Exercise 3: 1a. 3 h 35 min + 1 h 45 min = 4 h 80 min = 5 h 20 min 1b. Barcelona to Valencia 3 h 35 min = 215 min Valencia to Sevilla 1 h 45 min = 105 min longer 215 min – 105 min = 110 min or 1 h 50 min 2a. 2 h 15 min + 1 h 55 min = 3 h 70 min = 4 h 10 min 2b. 2 h 15 min - 1 h 55 min = 135 min - 115 min = 20 min 1. Colin John Ben 2. B A C 3. Tricia Ruby Peter
141 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed. 3a. 58 min + 1 h 17 min = 1 h 75 min = 2 h 15 min 3b. 1 h 17 min = 77 min 77 min – 58 min = 19 min 4a. 1 h 5 min + 50 min = 1 h 55 min 4b. 1 h 5 min = 65 min 65 min - 47 min = 18 min 5a. 1h 1h 15 min 6.15 pm 7.15 pm 8.15 pm 8.30 pm 1 h + 1 h + 15 min = 2 h 15 min 5b. 30 min 20 min 8.30 pm 9 pm 9.20 pm 30 min + 20 min = 50 min 6a. 1h 1h 1h 50 min 9.30 am 10.30 am 11.30 am 12.30 pm 1.20 pm 1 h + 1 h + 1 h + 50 min = 3 h 50 min 6b. 1 day 3 h 50 min = 230 min Monday to Saturday 6 days 6 x 230 = 1380 min = 23 hours 7a. Duration 45 min + 20 min + 55 min = 120 min or (2 h) 2h 3 pm 5 pm Start time 3 pm 7b. Total training time 45 min + + 20 min + 55 min = 120 min or 2 h
142 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed. 8. 25 min 30 min 3h 4.35 pm 5 pm 5.30 pm 8.30 pm Entire Duration 3 h + 30 min + 25 min = 3 h 55 min or (235 min) Time spent on sewing dress 235 min – 40 min = 195 min = 3 h 15 min 9a. 2h 15 min 4.15 pm 6.15 pm 6.30 pm Moana had dinner at 6.30 pm 9b. 95 min = 1 h 35 min 1h 35 min 7.10 pm 8.10 pm 8.45 pm She completed the jigsaw puzzle at 8.45 p.m. 10a. 1 h + 2 h 15 min = 3 h 15 min 3h 15 min 9 am 12 pm 12.15 pm James would finish his lunch at 12.15 p.m. 10b. 3 h 15 min 1.00 pm 4.00 pm 4.15 pm He would make his way home at 4.15 p.m. 11a. 30 min 45 min 10 min 22 min 10.35 am 11.05 am 11.50 am 12 pm 12.22 pm Or add duration first, then draw time line They would arrive at Trevi Fountain 12.22 p.m. 11b. 1 h + 27 min + 30 min + 20 min + 45 min = 1 h 122 min 122 min = 2 h 2 min Total time taken 3 h 2 min 3 h 2 min 2.15 pm 5.15 pm 5.17 pm They reached the hotel 5.17 p.m. 12. End time 7.55 pm Duration 85 min = 1 h 25 min 25 min 1 h 6.30 am 6.55 am 7.55 am She started baking at 6.30 a.m. 13. 45 min + 8 h 40 min + 45 min = 8 h 130 min 130 min = 2 h 10 min 8 h 130 min = 10 h 10 min 10 min 4 h 6h 8.05 am 8.15 am 12.15 pm 6.15 pm Doreen left her house at 8.05 a.m.
143 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed. Statement True / False 1 Mrs Goh left her house at 7.15 a.m. True 2 Mrs Goh spent 45 minutes to travel from her home to the supermarket. False 3 Mrs Goh spent 90 minutes at the supermarket. True 4 Mrs Goh left for home at 9.30 a.m. False 14. 15 min 20 min 1.45 pm 2 pm 2.20 pm 15 min + 20 min + 45 min = 80 min 80 min = 1 h 20 min Ans: 1 h 20 min 15. Breakfast 1 h 30 min 30 min 50 min = 90 min 35 min 6.45 a.m. 7.15 am 8.05 a.m. 9.35 am 10.10 am Woke up left home reach SM Left SM reach home
Boost! Math Primary 3 Lesson 42: Time 2 Answer Key 144 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed. Section A (2 marks each) 1) 4 2) 3 3) 4 4) 3 5) 4 6) 1 7) 1 8) 3 9) 4 10) 3 Section B (2 marks each) 11. 1 , 1 , 1 6 5 4 12. +1 +1 +1 +1 +1 1 , , 3 , 4 , 5 , 6 8 24 32 40 48 +8 +8 +8 +8 +8 13. 1 h = 60 min 1 h 45 min = 60 min + 45 min = 105 min 14. 5 h = 300 min 315 min = 5 h 15 min 15. 4 kg 300 g = 4 300 g 16. (a) $36.43 = 3643 ¢ (A1) (b) 1598 ¢ = $15.98 (A1) 3 2 6 6 17. 1 + 1 = 2 + 3 (M1) 6 = 5 (A1) 18. No of muffins given away 20 – 13 (M1) = 7 20 Fraction of muffins given away 7 (A1)
145 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed. 19. 5 km = 30 min (5 x 3) km = (3 x 30) min (M1) 15 km = 90 min = 1h 30 min (A1) 20. 1 h 1 h 5 min 2.15 p.m. 3.15 p.m. 4.15 p.m. 4.20 p.m. 1 h + 1 h + 5 min = 2 h 5 min Section C: Question 21 to 24 carry 3 marks each. Questions 25 and 26 carry 4 marks each. 21. 2 units 834 – 52 [M1] = 782 1 unit 782 ÷ 2 = 391 [M1] [A1] Ans: 391 stamps 22. Fraction of seats occupied by women = 10 - 1 - 1 10 5 10 [M1] [M1] [A1] = 10 - 2 - 1 10 10 10 = 7 10 Ans: 23. 3 units = 530 cm – 80 cm – 150 cm (M1) = 300 cm 1 unit = 300 cm ÷ 3 = 100 cm Length of String B = 100 cm (A1) Length of String C = 100 cm + 150 cm = 250 cm Ans (a): 100 cm Ans (b): 250 cm (A1) String A String B String C 80 cm 150 cm 530 cm Shawn Kristen 52 834
146 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed. 24. 2 units = 42 6 units = 3 x 42 (M2) = 126 (A1) Ans: 126 trading cards 25. 1 h 1 h 15 min 1 h 9 a.m. 10 a.m 11 a.m. 11.15 a.m.12.15 p.m. Number line working: Ans (a): 12.15 p.m. [M1] [A1] 1 h 20 min 45 min 1 p.m. 2 p.m. 2.20 pm 3.05 pm Number line working: Ans (b): 45 min [M1] [A1] 8 4 26. (a) Fraction of lemon tart eaten in total = 3 + 1 (M1) = 3 + 2 8 8 8 = 5 (A1) Ans (a): 5 8 8 8 (b) Fraction of lemon tart Bella kept for her parents = 8 - 5 (M1) 8 = 3 (A1) Ans (b): 3 8 Ben Ali ? 42
Boost! Math Primary 3 Lesson 43: Angels, Perpendicular and Parallel Lines Answer Key 147 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed. 1. Accept any reasonable answers for (a) and (b). 2. (a) c, a, b (b) f, d, e 3. (a) right angle (b) acute angle (c) obtuse angle (d) acute angle (e) acute angle (f) obtuse angle (g) acute angle (h) right angle (i) obtuse angle 4. 5. 6. Exercise 2 (p.5) 1. (a) perpendicular lines (c) parallel lines (g) perpendicular lines (b) parallel lines (e) perpendicular lines (h) perpendicular lines (c) perpendicular lines (f) parallel lines (i) parallel lines 2. Tick boxes (b) and (c) only 3. A and C 4. B and D 5. Tick boxes (a), (c), (e) and (f) Number of sides No of angles inside the figure Number of right angles Number of acute angles Number of angles greater than a right angle (a) 7 7 1 3 3 (b) 9 9 2 3 4 (c) 11 11 5 2 4 (d) 11 11 2 4 5
148 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed. 6a) Line AB ⊥ Line BD Line BD ⊥ Line CD Line AB // Line CD 6b) EF ⊥ FG IE ⊥ EF IE // FG 6c) PJ ⊥ JK JP ⊥ PO JK // PO LM // ON 6d) RQ ⊥ QP LM // PO MN // LR 6e) VU ⊥ UT ST ⊥ TU QV // SR VU // ST 6f) AF ⊥ FE FE ⊥ ED AB // CD AF // BC AF // DE BC // DE 7) (a) and (b) Accept any line that is parallel to the given line for (a) and (b) (c) and (d) - Length of the line need not be the same as the given line. (c) (d) 8) (a) and (b) Accept any line that is perpendicular to the given line (c) (d) (e) (f) 9) Tutors to accept any other correct answers. Example:
149 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed. 10) The number of sides and number to angles are the same. 11) Accept any plausible answers.
Boost! Math Primary 3 Lesson 44: Area and Perimeter [1] Answer Key 150 2021 Copyright of PAL Solutions. No furtherreproductionanddistribution is allowed. Exercise 1 (p.1-2) 1b) 5 1c) 4 square units 1d) 2 square units 1e) 5 square units 1f) 5 square units 2a) 33 square units 2b) 24 square units 2c) 37 square units 2d) 40 square units 2e) 36 square units 2f) 26 square units Exercise 2 (p.3) Fig B: 21 Fig C: 17 x 4cm2 = 68 cm2 Fig D: 14 x 4cm2 = 56 cm2 e) Fig E: 17m² f) Fig F: 23 m² Exercise 3 (p.4) 1) 11 x 8 = 88 cm² 2) 8 x 8 = 64 cm² 3) 15 x 3 = 45 m² 4) 7 x 7 = 49 cm² Notes (p.5) 1a) 24 1b) 28 Exercise 4 (p.5-6) a) 22 b) 22 c) 22 d) 24 e) 32 Exercise 5 (p.7) a) 8 + 5 + 8 + 5 = 26 cm b) 3 + 3 + 3 + 3 = 12 cm c) 6 + 2 + 6 + 2 = 16 cm d) 4 + 4 + 2 = 10 cm e) 4 + 4 + 6 + 7 + 6 = 27 cm f) 20 + 13 + 20 + 13 = 66 m Exercise 6 (p.8) 1a) Area 12 x 4 = 48 m2 Perimeter 12 + 4 +12 + 4 = 32 m 1b) Area 3 x 3 = 9 m2 Perimeter 3 x 4 = 12 m 1c) Area 16 x 5 = 80 m2 Perimeter 16 + 5 +16 + 5 = 42 m 1d) Area 19 x 6 = 114 cm2 Perimeter 19 + 6 +19 + 6 = 50 cm 1e) Area 7 x 7 = 49 cm2 Perimeter 7 x 4 = 28 cm 1f) Area 8 x 4 = 32 m2 Perimeter 8 + 4 +8 + 4 = 24 m