Chap01

CH 1APTER Directed Numbers

1. Evaluate each of the following.

(a) 13 × (–10) (b) –7 × 3

= =

2. Solve the following problems.

(a) Palm oil is pumped into an empty tanker at 200 litres per minute. How much palm
oil is in the tanker after 5 minutes?

(b) Siti takes 4 vitamin tablets a day from a box of vitamin tablets. How many tablets
are eaten by Siti after 30 days?

3. Find the value for each of the following.

(a) –144 ÷ (–12) (b) –28 ÷ 4

= =

4. Solve the following problems.

(a) During a TV Quiz open to home viewer, a total of RM2884 was given out in 7 minutes.
How much money was given in a minute?

(b) 210 m3 water was pumped out from a swimming pool in 12 minutes. How much
water was pumped out in 2 minutes?

5. Find the values for each of the following.

(a) 15 – (–4) + (–7) (b) –8 + 0 – (–15)

= =

(c) 8 + 2 – (–10) (d) –6 + 5 – (–1)

= =

(e) 4 – (–2) – 17 (f) 15 – (–2) – (–3)

= =

(g) 25 – 2 + (–9) – 1 (h) 3 + (–8) + (–7)

= =

(i) –6 + (–5) + (–7) – (–4) (j) 5 + (–8) – (–9) + 7

= =

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6. Find the product for each of the following.

(a) –3 × (–8) × (–4) (b) 6 × (–6) × 7

= =

7. Compute each of the following.

(a) 168 ÷ (–7) ÷ (–4) (b) 150 ÷ (–5) ÷ 6

= =

8. Compute each of the following.

(a) 6 × (–12) ÷ 9 (b) 15 × (–4) ÷ 12

= =

9. Evaluate each of the following.

(a) –7 + 18 ÷ (–2) (b) –19 × 3 – 47

= =

(c) 21 ÷ (–7) + (–12) (d) 16 + 0 × (–15)

= =

(e) 21 – 24 ÷ (–3) – 10 (f) 81 ÷ (–9) – (–5) × 4

= =

(g) 30 ÷ (–5) × 8 – (–13)
=

10. Solve the following problems.

(a) (–15) is subtracted from (– 42). The difference is divided by 9. Find the quotient.

(b) Hot-air is pumped into a hot-air balloon at 50 ml per second. Some hot-air leaks out
at 15 ml per second. How much hot-air is there after —12 hour?

1 1. Complete the following number line.

–4 –3 –2

1 2. Arrange the following fractions in descending order.
–4 —14 , –2 —41 , –3 —25 , –1 —12 , –2 —21

1 3. Evaluate –5 —172 + 1–2 —31 2 and simplify the answer to the lowest term.

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14. Evaluate each of the following and simplify the answers to the lowest term.

(a) –3 —18 × 1 —115 (b) —172 ÷ 1– —14 2 (c) –1 —21 ÷ 1–1 —18 2

= = =

(d) – —274 ÷ 1 —16 (e) —185 ÷ 1– —52 2 (f) 2 —17 ÷ 1–6 —41 2

= = =

1 5. Complete the following number line.

–8 –7

16. Arrange the following decimals in ascending order.
3.2, –2.5, –3.6, 4.1, –1.2

17. Evaluate each of the following.

(a) –4.1 + (–1.6) (b) –4.61 – (–8.32) (c) –(–6.32) – 1.48

= = =

(d) –(2.15) – (–3.82) (e) –0.1 – (–0.08) (f) –3.24 + (–8.178)

= = =

18. Evaluate the following.

(a) 1.8 ÷ (–0.2) (b) –4.92 ÷ 1.2 (c) –6.3 × 2.6

= = =

(d) –11.4 ÷ (–5.7) (e) 24.96 ÷ (–3.2) (f) –17.3 × –0.4

= = =

19. Evaluate each of the following.

(a) 1.3 – 7 —51 (b) —175 + (–6)

= =

2 0. Evaluate each of the following.

(a) –5 —53 ÷ 1.2 (b) –13.5 × 1 —32

= =

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21. Evaluate the following.

(a) 31 —25 – (–0.7)4 × 2 —61 (b) 4.811 —61 – 22 ÷ 8 —13

= =

22. Mr. Chan’s shop lost 3.5% of his customers every month for 5 months. After a sales
promotion, the customers increased by 2 —53 % per month for the next 7 months. What is
the average change of customers in that year?

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