Whole numbers Ex-2.2
NCERT solutions for Maths Whole numbers
NCERT Solutions for Class 6 Maths Whole numbers
Class –VI
Mathematics
(Ex. 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 arrangement:
(a) 2 x 1768 x 50
(b) 4 x 166 x 25
(c) 8 x 291 x 125
(d) 625 x 279 x 16
(e) 285 x 5 x 60
(f) 125 x 40 x 8 x 25
Answer:
(a) 2 x 1768 x 50
= (2 x 50) x 1768
= 100 x 1768
= 176800
(b) 4 x 166 x 25
= (4 x 25) x 166
= 100 x 166
= 16600
(c) 8 x 291 x 125
= (8 x 125) x 291
= 1000 x 291
= 291000
(d) 625 x 279 x 16
= (625 x 16) x 279
= 10000 x 279
= 2790000
(e) 285 x 5 x 60
= 284 x (5 x 60)
= 284 x 300
= 85500
(f) 125 x 40 x 8 x 25
= (125 x 8) x (40 x 25)
= 1000 x 1000
= 1000000
NCERT Solutions for Class 6 Maths Exercise 2.2
Question 3.Find the value of the following:
(a) 297 x 17 + 297 x 3
(b) 54279 x 92 + 8 x 54279
(c) 81265 x 169 – 81265 x 69
(d) 3845 x 5 x 782 + 769 x 25 x 218
Answer:
(a) 297 x 17 + 297 x 3
= 297 x (17 + 3)
= 297 x 20
= 5940
(b) 54279 x 92 + 8 x 542379
= 54279 x (92 + 8)
= 54279 x 100
= 5427900
(c) 81265 x 169 – 81265 x 69
= 81265 x (169 – 69)
= 81265 x 100
= 8126500
(d) 3845 x 5 x 782 + 769 x 25 x 218
= 3845 x 5 x 782 + 769 x 5 x 5 x 218)
= 3845 x 5 x 782 + 3845 x 5 x 218
= 3845 x 5 x (782 + 218)
= 3845 x 5 x 1000
= 19225000
Question 4. Find the product using suitable properties:
(a) 738 x 103
(b) 854 x 102
(c) 258 x 1008
(d) 1005 x 168
Answer:
(a) 738 x 103
= 738 x (100 + 3)
= 738 x 100 + 738 x 3
= 73800 + 2214
= 76014
(b) 854 x 102
= 854 x (100 + 2)
= 854 x 100 + 854 x 2
= 85400 + 1708
= 87108
(c) 258 x 1008
= 258 x (1000 + 8)
= 258 x 1000 + 258 x 8
= 258000 + 2064
= 260064
(d) 1005 x 168
= (1000 + 5) x 168
= 1000 x 168 + 5 x 168
= 168000 + 840
= 168840
NCERT Solutions for Class 6 Maths Exercise 2.2
Question 5. A taxi-driver, filled his car petrol tank with 40 liters of petrol on Monday. The next day, he filled the tank with 50 liters of petrol. If the petrol costs ` 44 per liter, how much did he spend in all on petrol?
Answer:
Petrol filled on Monday = 40 liters
Petrol filled on next day = 50 liters
Total petrol filled = 90 liters
Now, Cost of 1 liter petrol = ` 44
Cost of 90 liters petrol = 44 x 90
= 44 x (100 – 10)
= 44 x 100 – 44 x 10
= 4400 – 440
= ` 3960
Therefore, he spent ` 3960 on petrol.
Question 6. A vendor supplies 32 liters of milk to a hotel in a morning and 68 liters of milk in the evening. If the milk costs ` 15 per liter, how much money is due to the vendor per day?
Answer:
Supply of milk in morning = 32 liters
Supply of milk in evening = 68 liters
Total supply = 32 + 68 = 100 liters
Now Cost of 1 liter milk = ` 15
Cost of 100 liters milk = 15 x 100 = ` 1500
Therefore, ` 1500 is due to the vendor per day.
NCERT Solutions for Class 6 Maths Exercise 2.2
Question 7. Match the following:
(i)425 x 136 = 425 x (6 + 30 + 100) (a) Commutativity under multiplication
(ii) 2 x 48 x 50 = 2 x 50 x 49 (b) Commutativity under addition
(iii) 80 + 2005 + 20 = 80 + 20 + 2005 (c) Distributivity multiplication under addition
Answer:
(i) 425 x 136 = 425 x (6 + 30 + 100) (c) Distributivity of multiplication over addition
(ii) 2 x 49 x 50 = 2 x 50 x 49 (a) Commutivity under multiplication
(iii) 80 + 2005 + 20 = 80 + 20 + 2005 (b) Commutivity under addition