NCERT Maths Class 6 | Chapter 2 Solutions | Whole Numbers

Chapter 2 of NCERT class 6 mathematics is about whole numbers. You will find practice problems solutions for class 6 maths chapter 2 here. You can find chapter wise solutions of class 6 NCERT maths here

CLASS 6 | LESSON 2 – WHOLE NUMBERS

Natural numbers along with zero form the collection of whole numbers.

Exercise 2.1

1. Write the next three natural numbers after 10999.

Ans. 11000, 11001, 11002

2. Write the three whole numbers occurring just before 10001.

Ans. 10000, 9999, 9998

3. Which is the smallest whole number?

Ans. Zero

4. How many whole numbers are there between 32 and 53?

Ans. 20

5. Write the successor of:

a. 2440701
b. 100199
c. 1099999
d. 2345670

Ans.

a. 24, 40,702
b. 1, 00,200
c. 11, 00,000
d. 23, 45,671

6. Write the predecessor of:

a. 94
b. 10000
c. 208090
d. 7654321

Ans.

a. 93
b. 9,999
c.2, 08,089
d. 76, 54,320

7. In each of the following pairs of numbers, state which whole number is on the left of the other number on the number line. Also write them with the appropriate sign(< ,>) between them.

a. 530, 503
b. 370, 307
c. 98765, 56789
d. 9830415, 10023001

Ans.

a.503 is on the left of 530: 503 < 530
b. 307 is on the left of 370: 307 < 370
c. 56,789 is on the left of 98,765: 56,789 < 98,765
d. 98,30,415 is on the left of 1,00,23,001: 98,30,415 < 1,00,23,001

8. Which of the following statements are true and which are false?

a. Zero is the smallest natural number. —- False
b. 400 is the predecessor of 399. —False
c. Zero is the smallest whole number. —-True
d. 600 is the successor of 599. —- True
e. All natural numbers are whole numbers. —- True
f. All whole numbers are natural numbers. —-False
g. The predecessor of a two digit number is never a single digit number. —-False
h. 1 is the smallest whole number. —- False
i. The natural number 1 has no predecessor. —-True
j. The whole number 1 has no predecessor. —- False
k. The whole number 13 lies between 11 and 12. —- False
l. The whole number 0 has no predecessor. —–True
m .The successor of a two digit number is always a two digit number. —False

EXERCISE 2.2

1. Find the sum by suitable rearrangement:

a. 837 + 208 + 363
b. 1962 + 453 +1538 + 647

Ans.

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

2. Find the product by suitable rearrangement:

a. 2 x 1768 x50
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

Ans.

a. (2 x 50) x 1768 = 100 x 1768 = 1, 76,800
b. (4 x 25) x 166 = 100 x 166 = 16,600
c. (8 x 125) x 291 = 1000 x 291 = 2, 91,000
d. (625 x 16) x 279 = 10000 x 279 = 27, 90,000
e. 285 x (5 x 60) = 285 x 300 = 85,500
f. (125 x 8) x (40 x 25) = 1000 x 1000 = 10, 00,000

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

Ans.

a. Applying distributive property
297 (17 +3) = 297 x 20 = 5,940
b. 54279 (92 + 8) = 54279 x 100 = 54, 27,900
c. 81265 (169 – 69) = 81265 x 100 = 81, 26,500
d. (3845 x 5) = 19,225
769 x 25 = 19,225
19,225 (782 + 218) = 19,225 x 1000 = 1, 92, 25,000

4. Find the product using suitable properties:

a. 738 x 103
b. 854 x 102
c. 258 x 1008
d. 1005 x 168

Ans.

a. 738 (100 +3) = 738 X 100 + 738 X 3 = 73800 + 2214 = 76,014
b. 854(100+2) = 854 x 100 + 854 x2 = 85400 + 1708 = 87,108
c. 258 (1000+8) = 258 x 1000 + 258 x 8 = 258000 + 2064 = 2, 60,064
d. (1000+5) 168 = 1000 x 168 + 5 x 168 = 168000 + 840 = 1, 68,840

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?

Ans. Petrol filled on Monday = 40 litres
Petrol filled on next day = 50 litres
Cost of one litre of petrol = 44 rupees
The amount he spend in all on petrol = (40 + 50) x 44 = 90 x 44 = 3960 rupees.

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 45 per litre, how much money is due to the vendor per day?

Ans. The amount of milk supplied in the morning = 32 litres
The amount of milk supplied in the evening = 68 litres
Cost of one litre of milk = 45 rupees
Total cost = (32 + 68) x 45 = 100 x 45 = 4500 rupees

7. Match the following

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

Ans.

i) Distributivity of multiplication over addition
ii) Commutativity under multiplication
iii) Commutativity under addition

EXERCISE 2.3

1.Which of the following will not represent zero:

a) 1 +0
b) 0 x 0
c) 0/2

d) (10-10)/2

Ans. 1 + 0

2. If the product of two whole numbers is zero, can we say that one or both of them will be zero? Justify through examples.

Ans. Yes, if we multiply any number with zero the product will be zero.

Example: 3 x 0 = 0, 6 x 0 = 0
If both numbers are zero, then the product also is zero.
Example: 0 x 0 = 0

3. If the product of two whole numbers is 1, can we say that one or both of them will be 1? Justify through examples.

Ans. Both of them will be one.
If only one number is one, then the product will not be one.
Example: 3 x 1 = 3, 5 x 1 = 5

4. Find using distributive property:

a) 728 x 101
b) 5437 x 1001
c) 824 x 25
d) 4275 x 125

e) 504 x 35

Ans.

a) 728 x 101 = 728 x ( 100 + 1) = 728 x 100 + 728 x 1 = 72800 + 728 = 73,528
b) 5437 x 1001 = 5437 x (1000 + 1) = 5437 x 1000 + 5437 x 1 = 5437000 + 5437 = 54,42,437
c) 824 x 25 = 824 x (20 +5) = 824 x 20 + 824 x 5 = 16,480 + 4120 = 20,600
d) 4275 x 125 = 4275 x (100 + 25) = 4275 x 100 + 4275 x 25 = 427500 + 106875 = 5,34,375
e) 504 x 35 = (500 + 4) x 35 = 500 x 35 + 4 x 35 = 17500 + 140 = 17,640

5. Study the pattern:

1 x 8 + 1 = 9
12 x 8 + 2 = 98
123 x 8 + 3 = 987
1234 x 8 + 4 = 9876
12345 x 8 + 5 = 98765

Write the next two steps. Can you say how the pattern works?

Ans. 123456 x 8 + 6 = 987654
1234567 x 8 + 7 = 9876543

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