These NCERT Solutions for Class 6 Maths Chapter 2 Whole Numbers Ex 2.2 Questions and Answers are prepared by our highly skilled subject experts.
NCERT Solutions for Class 6 Maths Chapter 2 Whole Numbers Exercise 2.2
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
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 × (5 × 60)
= 285 × 300 = 85500
(f) 125 × 40 × 8 × 25
= (125 × 8) × (40 × 25)
= 1000 × 1000 = 1000000
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 + 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)
= 3845 × 5 × 1000 = 19225000
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
(Using distributive property)
= 73800 + 2214 = 76014
(b) 854 × 102 = 854 × (100 + 2)
= 854 × 100 + 854 × 2
(Using distributive property)
= 85400 + 1708 = 87108
(c) 258 × 1008 = 258 × (1000 + 8)
= 258 × 1000 + 258 × 8
= 258000 + 2064 = 260064
(d) 1005 × 168 = (1000 +5) × 168
= 1000 × 168 + 5 × 168
= 168000 + 840 = 168840
Question 5.
A taxi driver filled his car petrol tank with 40 litres of petrol on Monday. The next day, he tilled the tank with 50 litres of petrol. If the petrol costs ₹ 44 per litre, how much did he spend in all on petrol?
Answer:
Petrol filled on Monday = 40 litres
Petrol filled on next day (i.e. Tue.) = 50 litres
Total petrol filled = 90 litres
Now, Cost of 1 litre petrol = ₹ 44
Cost of 90 litres petrol = 44 × 90 = 44 × (100 – 10)
= 44 × 100 – 44 × 10 = 4400 – 440
= ₹ 3960
Therefore, he spent ? 3960 on petrol.
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 ? 41 per litre, how much money is due to the vendor per day?
Answer:
Supply of milk in morning the = 32 litres
Supply of milk in the evening = 68 litres
The cost of milk = ₹ 45 per litre
= ₹ 45 × [32+68]= ₹ 45 × 100 = ₹ 4500
Therefore, ₹ 4500 is due to the vendor per day.
Question 7.
Match the following:
| Column I | Column II |
| (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 multiplication under addition. |
Answer:
(i) → (c), (ii) → (a), (iii) → (b)