Maharashtra Board Textbook Solutions for Standard Seven

Chapter 2 – Multiplication and Division of Integers

Practice Set 8

Multiply. 

(i) (– 5) × (– 7) 

Solution:

(– 5) × (– 7) = 35

 

(ii) (– 9) × (6) 

Solution:

(– 9) × (6) = – 54

 

(iii) (9) × (– 4) 

Solution:

(9) × (– 4) = – 36

 

(iv) (8) × (– 7) 

Solution:

(8) × (– 7) = – 56

 

(v) (– 124) × (– 1) 

Solution:

(– 124) × (– 1) = 124

 

(vi) (– 12) × (– 7) 

Solution:

(– 12) × (– 7) = 84

 

(vii) (– 63) × (– 7) 

Solution:

(– 63) × (– 7) = 441

 

(viii) (– 7) × (15)

Solution:

(– 7) × (15) = – 105

Practice set 9

1. Solve :

(i) (– 96) ÷ 16 

Solution:

(– 96) ÷ 16 = (1)×9616

∴ (– 96) ÷ 16 = (1)×16×616

∴ (– 96) ÷ 16 = (– 1) × 6

∴ (– 96) ÷ 16 = – 6

(ii) 98 ÷ (– 28) 

Solution:

98 ÷ (– 28) = 98(1)×28

∴ 98 ÷ (– 28) = 14×7(1)×14×2

∴ 98 ÷ (– 28) = 7(1)×2

∴ 98 ÷ (– 28) = 72

∴ 98 ÷ (– 28) = 72

(iii) (– 51) ÷ 68 

Solution:

(– 51) ÷ 68 = (1)×5168

∴ (– 51) ÷ 68 = (1)×17×317×4

∴ (– 51) ÷ 68 = (1)×34

∴ (– 51) ÷ 68 = 34

(iv) 38 ÷ (– 57)

Solution:

38 ÷ (– 57) = 38(1)×57

∴ 38 ÷ (– 57) = 19×2(1)×19×3

∴ 38 ÷ (– 57) = 2(1)×3

∴ 38 ÷ (– 57) = 23

∴ 38 ÷ (– 57) = 23

(v) (– 85) ÷ 20 

Solution:

(– 85) ÷ 20 = (1)×8520

∴ (– 85) ÷ 20 = (1)×17×54×5

∴ (– 85) ÷ 20 = (1)×174

∴ (– 85) ÷ 20 = 174

(vi) (– 150) ÷ (– 25) 

Solution:

(– 150) ÷ (– 25) = (1)×150(1)×25

∴ (– 150) ÷ (– 25) = 25×625

∴ (– 150) ÷ (– 25) = 6

(vii) 100 ÷ 60 

Solution:

100 ÷ 60 = 10060

∴ 100 ÷ 60 = 20×520×3

∴ 100 ÷ 60 = 53

(viii) 9 ÷ (– 54)

Solution:

9 ÷ (– 54) = 99(1)×54

∴ 9 ÷ (– 54) = 9(1)×9×6

∴ 9 ÷ (– 54) = 1(1)×6

∴ 9 ÷ (– 54) = 16

∴ 9 ÷ (– 54) = 16

(ix) 78 ÷ 65 

Solution:

78 ÷ 65 = 7865

∴ 78 ÷ 65 = 13×613×5

∴ 78 ÷ 65 = 65

(ix) 78 ÷ 65 

Solution:

78 ÷ 65 = 7865

∴ 78 ÷ 65 = 13×613×5

∴ 78 ÷ 65 = 65

(x) (– 5) ÷ (– 315)

Solution:

(– 5) ÷ (– 315) = (1)×5(1)×315

∴ (– 5) ÷ (– 315) = 55×63

∴ (– 5) ÷ (– 315) = 163

2 . Write three divisions of integers such that the fractional form of each will be 245.

Solution:

(i) 245 = (1)×24(1)×5

245 = 245

 

(ii) 245 = 2×242×5

245 = 4810

 

(iii) 245 = 10×2410×5

245 = 24050

3. Write three divisions of integers such that the fractional form of each will be 57.

Solution:

(i) \57 = 2×52×7

57\) = 1014

 

(ii) 57 = 5×55×7

57 = 2535

 

(iii) 57 = 3×53×7

57 = 1521

4. The fish in the pond below, carry some numbers. Choose any 4 pairs and carry out four multiplications with those numbers. Now, choose four other pairs and carry out divisions with these numbers.

For example, 

1. (– 13) × (– 15) = 195 

2. (– 24) ÷ 9 = 249 = 83

IMG 20231005 001737 Chapter 2 – Multiplication and Division of Integers

Solution:

Multiplication Pairs

(i) (– 13) × 9 = – 117  

(ii) 12 × 13 = 156  

(iii) 9 × (– 37) = – 333  

(iv) (– 15) × (– 8) = 120

 

Division Pairs

(i) – 28 ÷ 12 = 2812 = 1×2812 = 73

(ii) 12 ÷ 9 = 129 = 43

(iii) 9 ÷ (– 24) = 924 = 91×24 = 31×8 = 38

(iv) – 18 ÷ (– 27) = 1827 = 1×181×27 = 23