Page 305 - ICSE Math 7

Answers

Chapter 1 6. (a) –51 (b) 100
7. (a) 600 (b) –12,100 (c) 6,336 (d) –2,970
Exercise 1.1 8. (a) 36 (b) –882 (c) 7 (d) 18 9. 6a –5b – 3c; –6
1. (a) –1 0 1 2 3 4 5 6 10. (a) (b)

(b) –2 –1 0 1 2 3 11. 8.5°C –5 –4 –3 –2 –1 0 1 –2 –1 0 1 2
2. (a) –6 (b) 72 (c) –68
3. (a) –132 < –76 < –56 < 96 < 123 < 132 Think Smart
(b) –215 < –185 < –55 < 60 < 99 < 125 1. (a) +; – (b) –; – (c) ÷; – (d) +; + 2. –6 and –5
4. (a) 473 > 175 > 99 > –222 > –365 (Answers may vary)
(b) 216 > 156 > 0 > –74 > –88 > –193 Chapter 2

Exercise 1.2 Exercise 2.1
1. 34 2. 343 10 1 5 1
3
3. (a) 775 (b) –251 (c) 371 (d) 142 (e) –27 1. (a) 8 11 (b) 13 (c) 19 22 (d) 22 2
4. 42 5. (a) –1,617 (b) –3,630 (c) 1,620 (d) 1,140 2. (a) 26 (b) 121 (c) 113 (d) 1,389
6. (a) 12 (b) –13 (c) 0 (d) –1 (e) 175 (f) 13 7 9 5 107
7. (a) 40 (b) 92 (c) –53 (d) 4a – 2b + 4c (e) 0 3. (a) 35 15 (b) 38 117 (c) 105 66 60
,
,
,
,
60 60 52 52 75 75 75
Exercise 1.3 4. (a) 10 (b) 21 (c) 19
1. (a) 50 marks (b) 17 marks 13 25 24
2. (a) 76°C (b) 38°C (c) 50°C 3. ` 1,550 5. (a) 5 < 9 < 7 (b) 23 < 19 < 11
6
4. decrease of 2,000 feet; 18,000 feet 5. 31 marbles 12 10 6 15 29 36 24 12
46
6. (a) 5°F (b) 104°F (c) –40°F (c) 99 < 11 < 22 < 33
7. (a) 80°C (b) 32°C 8 7 9 29 9 5
6. (a) 15 > 20 > 35 (b) 42 > 16 > 24
Mental Maths
7
5
9 11
,
1. (a) False (b) False (c) False (d) True (c) 12 > 13 > 11 > 48 7. 45 8. 13 15 or 11 13
,
36
30
47
15 17
(e) True (f) False
2. (a) = (b) < (c) < (d) > (e) < (f) < (g) > (h) < Exercise 2.2
7
1
5
1
3. (a) × Multiplicand (–8) 1. (a) 10 (b) 24 (c) 17 (d) 11 41 (e) 5 (f) 3 18
60
96
6
(–7)
(–6)
Multiplier (–7) (–36) (–42) (–48) 2. (a) 99 m (b) 1 h (c) 1 17 kg (d) 20 20 (e) 11
1
6
51
18
3
45
2
8
42
49
56
7
8
7
3
7
8 (–48) (–56) (–64) (f) 141 3. (a) (b) 13 (c) 11 (d) 31
3
1
4. (a) (b) (c) 1 19 (d) 17 1
(b) Dividend 4 9 5 2 33 13 3 1
÷
104
(b) 8 (c) 2
Divisor (–13) (–52) (–26) (–156) 5. (a) 21 79 (g) 3 15 (h) –1 (d) (e) 6
7
10
3
30
12
(–8)
4
(–4)
(f) 2
13
39
2 (–26) 52 (–78) 168 19
Exercise 2.3
Practice Time 13
1. (a) closed (b) not closed (c) closed (d) not closed 1. 44,200 2. ` 19,200 3. 48 60 kg 4. 44 kg; 22 kg
1 1 1
2. (a) not closed (b) closed (c) not closed 5. Tia –` 304; Simran –` 114 6. ; ; 7. 72 ft 8. 1
3. 9 ; 7 2 3 6 6
4. (a) 1, 2, 3, 4, 5 (b) 0, 1, 2, 3, 4, 5 Mental Maths
(c) –5, –4, –3, –2, –1, 0, 1, 2, 3, 4, 5 1. (a) (i) (b) (i) (c) (ii) (d) (ii) (e) (i) (f) (iii)
5. (a) 192 (b) 0 (c) 1,200 2. (a) False (b) False (c) True (d) False (e) False
291