NCERT solution class 6 mathematics Chapter 2 Whole Number Exercise 2.2 ~ evidya

Exercise 2.2

Ex-2.1
Ex-2.2
Ex-2.3

Page No 40:

Q 1 - Ex 2.2 - Whole Numbers - Chapter 2 - Class 6th NCERT Maths

Question 1:

Find the sum by suitable rearrangement:
(a) 837 + 208 + 363 (b) 1962 + 453 + 1538 + 647

Answer:

(a) 837 + 208 + 363 = (837 + 363) + 208
= 1200 + 208 = 1408
(b) 1962 + 453 + 1538 + 647 = (1962 + 1538) + (453 + 647)
= 3500 + 1100 = 4600

Q 2 - Ex 2.2 - Whole Numbers - Chapter 2 - Class 6th NCERT Maths

Question 2:

Find the product by suitable rearrangement:
(a) 2 × 1768 × 50 (b) 4 × 166 × 25
(c) 8 × 291 × 125 (d) 625 × 279 × 16
(e) 285 × 5 × 60 (f) 125 × 40 × 8 × 25

Answer:

(a) 2 × 1768 × 50 = 2 × 50 × 1768
= 100 × 1768 = 176800
(b) 4 × 166 × 25 = 4 × 25 × 166
= 100 × 166 = 16600
(c) 8 × 291 × 125 = 8 × 125 × 291
= 1000 × 291 = 291000
(d) 625 × 279 × 16 = 625 × 16 × 279
= 10000 × 279 = 2790000
(e) 285 × 5 × 60 = 285 × 300 = 85500
(f) 125 × 40 × 8 × 25 = 125 × 8 × 40 × 25
= 1000 × 1000 = 1000000

Q 3 - Ex 2.2 - Whole Numbers - Chapter 2 - Class 6th NCERT Maths

Question 3:

Find the value of the following:
(a) 297 × 17 + 297 × 3 (b) 54279 × 92 + 8 × 54279
(c) 81265 × 169 − 81265 × 69 (d) 3845 × 5 × 782 + 769 × 25 × 218

Answer:

(a) 297 × 17 + 297 × 3 = 297 × (17 + 3)
= 297 × 20 = 5940
(b) 54279 × 92 + 8 × 54279 = 54279 × 92 + 54279 × 8
= 54279 × (92 + 8)
= 54279 × 100 = 5427900
(c) 81265 × 169 − 81265 × 69 = 81265 × (169 − 69)
= 81265 × 100 = 8126500
(d) 3845 × 5 × 782 + 769 × 25 × 218
= 3845 × 5 × 782 + 769 × 5 × 5 × 218
= 3845 × 5 × 782 + 3845 × 5 × 218
= 3845 × 5 × (782 + 218)
= 19225 × 1000 = 19225000

Q 4 - Ex 2.2 - Whole Numbers - Chapter 2 - Class 6th NCERT Maths

Question 4:

Find the product using suitable properties.
(a) 738 × 103 (b) 854 × 102
(c) 258 × 1008 (d) 1005 × 168

Answer:

(a) 738 × 103 = 738 × (100 + 3)
= 738 × 100 + 738 × 3 (Distributive property)
= 73800 + 2214
= 76014
(b) 854 × 102 = 854 × (100 + 2)
= 854 × 100 + 854 × 2 (Distributive property)
= 85400 + 1708 = 87108
(c) 258 × 1008 = 258 × (1000 + 8)
= 258 × 1000 + 258 × 8 (Distributive property)
= 258000 + 2064 = 260064
(d) 1005 × 168 = (1000 + 5) × 168
= 1000 × 168 + 5 × 168 (Distributive property)
= 168000 + 840 = 168840

Q 5 - Ex 2.2 - Whole Numbers - Chapter 2 - Class 6th NCERT Maths

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?

Answer:

Quantity of petrol filled on Monday = 40 l
Quantity of petrol filled on Tuesday = 50 l
Total quantity filled = (40 + 50) l
Cost of petrol (per l) = Rs 44
Total money spent = 44 × (40 + 50)
= 44 × 90 = Rs 3960

Q 6 - Ex 2.2 - Whole Numbers - Chapter 2 - Class 6th NCERT Maths

Page No 41:

Question 6:

A vendor supplies 32 litres of milk to a hotel in the morning and 68 litres of milk in the evening. If the milk costs Rs 15 per litre, how much money is due to the vendor per day?

Answer:

Quantity of milk supplied in the morning = 32 l
Quantity of milk supplied in the evening = 68 l
Total of milk per litre = (32 + 68) l
Cost of milk per litre = Rs 15
Total cost per day = 15 × (32 + 68)
= 15 × 100 = Rs 1500

Q 7 - Ex 2.2 - Whole Numbers - Chapter 2 - Class 6th NCERT Maths

Question 7:

Match the following:
(i) 425 × 136 = 425 × (6 + 30 + 100)
(a) Commutativity under multiplication
(ii) 2 × 49 × 50 = 2 × 50 × 49
(b) Commutativity under addition
(iii) 80 + 2005 + 20 = 80 + 20 + 2005
(c) Distributivity of multiplication over addition

Answer:

(i) 425 × 136 = 425 × (6 + 30 + 100) [Distributivity of multiplication over addition]
Hence, (c)
(ii) 2 × 49 × 50 = 2 × 50 × 49 [Commutativity under multiplication]
Hence, (a)
(iii) 80 + 2005 + 20 = 80 + 20 + 2005 [Commutativity under addition]
Hence, (b)

Monday, May 25, 2020