Whole Numbers

Ncert Exercise 2.2 solution part-2 class 6 math

Question (3) Find the value of the following:

(a) 297 × 17 + 297 × 3

Solution

Given, 297 × 17 + 297 × 3

Using associative property of multiplication over addition, we get

297 × (17 + 3)

= 297 × 20

= 5940

Thus, Answer = 5940

(b) 54279 × 92 + 8 × 54279

Solution

Given, 54279 × 92 + 8 × 54279

Using associative property of multiplication over addition, we get

54279 × (92 + 8)

= 54279 × 100

= 5427900

Thus, Answer = 5427900

(c) 81265 × 169 – 81265 × 69

Solution

Given, 81265 × 169 – 81265 × 69

Using associative property, we get

81265 × (169 ̵ 69)

= 81265 × 100

= 8126500

Thus, Answer = 81265

(d) 3845 × 5 × 782 + 769 × 25 × 218

Solution

Given, 3845 × 5 × 782 + 769 × 25 × 218

Using associative property, we get

(3845 × 5) × 782 + (769 × 25) × 218

= 19225 × 782 + 19225 × 218

Now, using associative property over addition, we get

= 19225 × (782 + 218)

= 19225 × 1000

= 19225000

Thus, Answer = 19225000

Question (4) find the product using suitable properties

(a) 738 × 103

Solution

Given, 738 × 103

Using distributive property, we get

738 × (100 + 3)

= (738 × 100) + (738 × 3)

= 73800 + 2214

= 76,014

Thus, Answer = 76,014

(b) 854 × 102

Solution

Given, 854 × 102

Using distributive property, we get

854 × (100 + 2)

= (854 × 100) + (854 × 2)

= 85400 + 1708

= 87,108

Thus, Answer = 87,108

(c) 258 × 1008

Solution

Given, 258 × 1008

Using distributive property, the given expression can be written as

258 × (1000 + 8)

= (258 × 1000) + (258 × 8)

= 2,58,000 + 2064

= 2,60,064

Thus, Answer = 2,60,064

(d) 1005 × 168

Solution

Given, 1005 × 168

Using distributive property, the given expression can be written as

(1000 + 5) × 168

= (1000 × 168) + (5 × 168)

= 1,68,000 + 840

= 1,68,840

Thus, Answer = 1,68,840

Question (5) A taxi driver filled his car petrol tank with 40 litres of petrol on Monday. The next day, he filled the tank with 50 litres of petrol. If the petrol costs Rs 44 per litre, how much did he spend in all on petrol?

Solution

Given, petrol filled on Monday = 40 litre

And, petrol filled on next day = 50 litre

And, the cost of petrol = Rs 44 per litre

Thus, total expenditure on petrol = ?

Total petrol filled = Petrol filled on Monday + Petrol filled on next day

= 40 litre + 50 litre = 90 litre

Thus, total petrol filled = 90 litre

And, as given the cost of petrol per litre = Rs 44

This, means cost of 1 litre of petrol = Rs 44

Thus, cost of 90 litre of petrol = Rs 44 × 90

= 44 × 90

Using distributive property, the above expression can be written as

= (40 + 4) × 90

= (40 × 90) + (4 × 90)

= 3600 + 360

= 3960

Thus, total expenditure on petrol = Rs 3960 Answer

Question (7) Match the following:

Answer