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Question 1:

Write the next three whole numbers after 30999.

The next three whole numbers after 30999 are 31000, 31001 and 31002.

Question 2:

Write the three whole numbers occurring just before 10001.

Three whole numbers occurring just before 10001 are as follows:

10001 − 1 = 10000
10000 − 1 = 9999
9999 − 1 = 9998

∴ The three whole numbers just before 10001 are 10000, 9999 and 9998.

Question 3:

How many whole numbers are there between 1032 and 1209?

Number of whole numbers between 1032 and 1209 = (1209 − 1032) − 1
= 177 − 1
= 176

Question 4:

Which is the smallest whole number?

0 (zero) is the smallest whole number.

All the natural numbers along with 0 are called whole numbers.

Question 5:

Write the successor of:
(i) 2540801
(ii) 9999
(iii) 50904
(iv) 61639
(v) 687890
(vi) 5386700
(vii) 6475999
(viii) 9999999

(i) Successor of 2540801 = 2540801 + 1 = 2540802
(ii) Successor of 9999 = 9999 + 1 = 10000
(iii) Successor of 50904 = 50904 + 1 = 50905
(iv) Successor of 61639 = 61639 + 1 = 61640
(v) Successor of 687890 = 687890 + 1 = 687891
(vi) Successor of 5386700 = 5386700 + 1 = 5386701
(vii) Successor of 6475999 = 6475999 + 1 = 6476000
(viii) Successor of 9999999 = 9999999 + 1 = 10000000

Question 6:

Write the predecessor of:
(i) 97
(ii) 10000
(iii) 36900
(iv) 7684320
(v) 1566391
(vi) 2456800
(vii) 100000
(viii) 1000000

(i) Predecessor of 97 = 97 − 1 = 96
(ii) Predecessor of 10000 = 10000 − 1 = 9999
(iii) Predecessor of 36900 = 36900 − 1 = 36899
(iv) Predecessor of 7684320 = 7684320 − 1 = 7684319
(v) Predecessor of 1566391 = 1566391 − 1 = 1566390
(vi) Predecessor of 2456800 = 2456800 − 1 = 2456799
(vii) Predecessor of 100000 = 100000 − 1 = 99999
(viii) Predecessor of 1000000 = 1000000 − 1 = 999999

Question 7:

Write down three consecutive whole numbers just preceding 7510001.

The three consecutive whole numbers just preceding 7510001 are as follows:

7510001 − 1 = 7510000
7510000 − 1 = 7509999
7509999 − 1 = 7509998

∴ The three consecutive numbers just preceding 7510001 are 7510000, 7509999 and 7509998.

Question 8:

Write (T) for true and (F) for false against each of the following statements:
(i) Zero is the smallest natural number.
(ii) Zero is the smallest whole number.
(iii) Every whole number is a natural number.
(iv) Every natural number is a whole number.
(v) 1 is the smallest whole number.
(vi) The natural number 1 has no predecessor.
(vii) The whole number  1 has no predecessor.
(viii) The whole number 0 has no predecessor.
(ix) The predecessor of a two-digit number is never a single-digit number.
(x) The successor of a two-digit number is always a two-digit number.
(xi) 500 is the predecessor of 499.
(xii) 7000 is the successor of 6999.

(i) False. 0 is not a natural number.1 is the smallest natural number.
(ii) True.
(iii) False. 0 is a whole number but not a natural number.
(iv) True. Natural numbers include 1,2,3 ..., which are whole numbers.
(v) False. 0 is the smallest whole number.
(vi) True. The predecessor of 1 is 1 − 1 = 0, which is not a natural number.
(vii) False. The predecessor of 1 is 1 − 1 = 0, which is a whole number.
(viii) True. The predecessor of 0 is 0 − 1 = −1, which is not a whole number.
(ix) False. The predecessor of a two-digit number can be a single digit number. For example, the predecessor of 10 is 10 − 1, i.e., 9.
(x) False. The successor of a two-digit number is not always a two-digit number. For example, the successor of 99 is 99 + 1, i.e., 100.
(xi) False. The predecessor of 499 is 499 − 1, i.e., 498.
(xii) True. The successor of 6999 is 6999 + 1, i.e., 7000.

Question 1:

Fill in the blanks to make each of the following a true statement:
(i) 458 + 639 = 639 + ......
(ii) 864 + 2006 = 2006 + ......
(iii) 1946 + ...... = 984 + 1946
(iv) 8063 + 0 = ......
(v) 53501 + (574 + 799) = 574 + (53501 + ......)

(i) 458 + 639 = 639 + 458
(ii) 864 + 2006 = 2006 + 864
​(iii) 1946 + 984 = 984 + 1946
(iv) 8063 + 0 = 8063
(v) 53501 + (574 + 799) = 574 + (53501 + 799)

Question 2:

Add the following numbers and check by revershing the order of the addends:
(i) 16509 + 114
(ii) 2359 + 548
(iii) 19753 + 2867

(i) 16509 + 114 = 16623
By reversing the order of the addends, we get:
114 + 16509 = 16623
∴ 16509 + 114 = 114 + 16509

(ii) 2359 + 548 = 2907
By reversing the order of the addends, we get:
548 + 2359 = 2907
∴ 2359 + 548 = 548 + 2359

(iii) 19753 + 2867 = 22620
By reversing the order of the addends, we get:
2867 + 19753 = 22620
∴ 19753 + 2867 = 2867 + 19753

Question 3:

Find the sum: (1546 + 498) + 3589.
Also, find the sum: 1546 + (498 + 3589).
Are the two sums equal?
State the property satisfied.

We have:

(1546 + 498) + 3589 = 2044 + 3589 = 5633

Also, 1546 + (498 + 3589) = 1546 + 4087 = 5633

Yes, the two sums are equal.

The associative property of addition is satisfied.

Question 4:

Determine each of the sums given below using suitable rearrangement.
(i) 953 + 707 + 647
(ii) 1983 + 647 + 217 + 353
(iii) 15409 + 278 + 691 + 422
(iv) 3259 + 10001 + 2641 + 9999
(v) 1 + 2 + 3 + 4 + 96 + 97 + 98 + 99
(vi) 2 + 3 + 4 + 5 + 45 + 46 + 47 + 48

(i) 953 + 707 + 647
953 + (707 + 647)                                   (Using associative property of addition)
= 953 + 1354
= 2307

(ii) 1983 + 647 + 217 + 353
(1983 + 647)  + (217 +353)                    (Using associative property of addition)
= 2630 + 570
=  3200

(iii) 15409 + 278 + 691 + 422
(15409 + 278) + (691 + 422)                     (Using associative property of addition)
= 15687 + 1113
= 16800

(iv) 3259 + 10001 + 2641 + 9999
(3259 + 10001) + (2641 +  9999)             (Using associative property of addition)
= 13260 + 12640
= 25900

(v)1 + 2 + 3 + 4 + 96 + 97 + 98 + 99
(1 + 2 + 3 + 4) + (96 + 97 + 98 + 99)       (Using associative property of addition)
= (10) + (390)
=  400

(vi) 2 + 3 + 4 + 5 + 45 + 46 + 47 + 48
(2 + 3 + 4 + 5) + (45 + 46 + 47 + 48)                 (Using associative property of addition)
= 14 + 186
= 200

Question 5:

Find the sum by short method:
(i) 6784 + 9999
(ii) 10578 + 99999

(i)  6784 + 9999
=  6784 + (10000 − 1)
=  (6784 + 10000) − 1                              (Using associative property of addition)
= 16784 − 1
= 16783

(ii) 10578 + 99999
= 10578 + (100000 − 1)
= (10578 + 100000) − 1                         (Using associative property of addition)
= 110578 − 1
= 110577

Question 6:

For any whole numbers a, b, c, is it true that (a + b) + c = a + (c + b)? Give reasons.

For any whole numbers a, b and c, we have:
(a + b) + c = a + b + c​)

Let a = 2, b = 3 and c = 4 [we can take any values for a, b and c]

LHS = (a + b​) + c
(2 + 3) + 4
= 5 + 4
= 9

RHS = a + (c + b)
= a + (b + c)       [∵ Whole numbers follow the commutative law]
= 2 + (3 + 4)
= 2 + 7
= 9

∴ This shows that associativity (in addition) is one of the properties of whole numbers.

Question 7:

Complete each one of the following magic squares by supplying the missing numbers:
(i)

 9 2 5 8
(ii)
 16 2 10 4
(iii)
 2 15 16 9 12 7 10 14 17
(iv)
 18 17 4 14 11 9 10 19 16

In a magic square, the  sum of each row is equal to the sum of each column and the sum of each main diagonal.  By using this concept, we have:
(i)

 4 9 2 3 5 7 8 1 6

(ii)
 16 2 12 6 10 14 8 18 4

(iii)
 2 15 16 5 9 12 11 6 13 8 7 10 14 3 4 17

(iv)
 7 18 17 4 8 13 14 11 12 9 10 15 19 6 5 16

Question 8:

Write (T) for true and (F) for false for each of the following statements:
(i) The sum of two odd numbers is an odd number.
(ii) The sum of two even numbers is an even number.
(iii) The sum of an even number and an odd number is an odd number.

(i)  F (false). The sum of two odd numbers may not be an odd number. Example: 3 + 5 = 8, which is an even number.

(ii) T (true). The sum of two even numbers is an even number. Example: 2 + 4 = 6, which is an even number.

(iii) T (true). The sum of an even and an odd number is an odd number. Example: 5 + 4 = 9, which is an odd number.

Question 1:

(i) 6237 − 694
(ii) 21205 − 10899
(iii) 100000 − 78987
(iv) 1010101 − 656565

(i) Subtraction: 6237 − 694 = 5543
Addition: 5543 + 694 = 6237

(ii) Subtraction: 21205 − 10899 = 10306
Addition: 10306 + 10899 = 21205

(iii) Subtraction: 100000 − 78987 = 21013
Addition: 21013 + 78987 = 100000

(iv) Subtraction: 1010101 − 656565 = 353536
Addition: 353536 + 656565 = 1010101

Question 2:

Replace each * by the correct digit in each of the following:
(i)
(ii)
(iii)
(iv)

(i)   917 − *5* =  5*8

⇒ 917 − 359 =  558

(ii) 6172 − **69 =  29**

⇒ 6172 − 3269 = 2903

(iii) 5001003 − **6987 =  484****

⇒ 5001003 − 155987 = 4845016

(iv)  1000000 − ****1 = *7042*

⇒ 1000000 − 29571 = 970429

Question 3:

Find the difference:
(i) 463 − 9
(ii) 5632 − 99
(iii) 8640 − 999
(iv) 13006 − 9999

(i) 463 − 9
= 463 − 10 + 1
= 464 − 10
= 454

(ii) 5632 − 99
= 5632 − 100 + 1
= 5633 − 100
=  5533

(iii) 8640 − 999
= 8640 − 1000 + 1
= 8641 − 1000
= 7641

(iv) 13006 − 9999
= 13006 − 10000 + 1
= 13007 − 10000
= 3007

Question 4:

Find the difference between the smallest number of 7 digits and the largest number of 4 digits.

Smallest seven-digit number = 1000000
Largest four-digit number = 9999
∴ Their difference = 1000000 − 9999
=1000000 − 10000 + 1
=1000001 − 10000
=990001

Question 5:

Ravi opened his account in a bank by depositing Rs 136000. Next day he withdrew Rs 73129 from it. How much money was left in his account?

Money deposited by Ravi = Rs 1,36,000
Money withdrawn by Ravi= Rs 73,129
Money left in his account  =  money deposited − money withdrawn
= Rs (136000 − 73129)
= Rs 62871

∴ Rs 62,871 is left in Ravi's account.

Question 6:

Mrs Saxena withdrew Rs 100000 from her bank account. She purchased a TV set for Rs 38750, a refrigerator for Rs 23890 and jewellery worth Rs 35560. How much money was left with her?

Money withdrawn by Mrs Saxena  = Rs 1,00,000
Cost of the TV set = Rs 38,750
Cost of the refrigerator = Rs 23,890
Cost of the jewellery = Rs 35,560
Total money spent = Rs (38750 + 23890 + 35560) = Rs 98200

Now, money left = money withdrawn − money spent
= Rs (100000 − 98200)
= Rs 1800

∴ Rs 1,800 is left with Mrs Saxena.

Question 7:

The population of a town was 110500. In one year it increased by 3608 due to new births. However, 8973 persons died or left the town during the year. What was the population at the end of the year?

Population of the town = 110500
Increased population = 110500 + 3608 = 114108
Number of persons who died or left the town = 8973
Population at the end of the year = 114108 − 8973 = 105135

∴ The population at the end of the year will be 105135.

Question 8:

Find the whole number n when:
(i) n + 4 = 9
(ii) n + 35 = 101
(iii) n − 18 = 39
(iv) n − 20568 = 21403

(i) n + 4 = 9
⇒ n = 9 − 4 = 5

(ii) n + 35 = 101
⇒ n = 101 − 35 = 66

(iii) n - 18 = 39
⇒ n =  18 + 39 = 57

(iv) n  20568 = 21403
⇒ n  = 21403 + 20568 = 41971

Question 1:

Fill in the blanks to make each of the following a true statement:
(i) 246 × 1 = ......
(ii) 1369 × 0 = .......
(iii) 593 × 188 = 188 × .......
(iv) 286 × 753 = ...... × 286
(v) 38 × (91 × 37) = ...... × (38 × 37)
(vi) 13 × 100 × ...... = 1300000
(vii) 59 × 66 + 59 × 34 = 59 × (...... + ......)
(viii) 68 × 95 = 68 × 100 − 68 × .......

(i) 246 × 1 = 246
(ii) 1369 × 0 = 0
(iii) 593 × 188  = 188 × 593
(iv) 286 × 753 = 753 × 286
(v) 38 × (91 × 37) = 91 × (38 × 37)
(vi) 13 × 100 × 1000 = 1300000
(vii) 59 × 66 + 59  ×  34 = 59 × ( 66 + 34)
(viii) 68 × 95 = 68 × 100 − 68 × 5

Question 2:

State the property used in each of the following statements:
(i) 19 × 17 = 17 × 19
(ii) (16 × 32) is a whole number
(iii) (29 × 36) × 18 = 29 × (36 × 18)
(iv) 1480 × 1 = 1480
(v) 1732 × 0 = 0
(vi) 72 × 98 + 72 × 2 = 72 × (98 + 2)
(vii) 63 × 126 − 63 × 26 = 63 × (126 − 26)

(i) Commutative law in multiplication
(ii) Closure property
(iii) Associativity of multiplication
(iv) Multiplicative identity
(v) Property of zero
(vi) Distributive law of multiplication over addition
(vii) Distributive law of multiplication over subtraction

Question 3:

Find the value of each of the following using various properties:
(i) 647 × 13 + 647 × 7
(ii) 8759 × 94 + 8759 × 6
(iii) 7459 × 999 + 7459
(iv) 9870 × 561 − 9870 × 461
(v) 569 × 17 + 569 × 13 + 569 × 70
(vi) 16825 × 16825 − 16825 × 6825

(i) 647 × 13 + 647 × 7
=  647 × (13 + 7)
= 647 ×  20
= 12940                                 (By using distributive property)

(ii)  8759 × 94 + 8759 × 6
= 8759 × (94 + 6)
= 8759 ×  100
= 875900                              (By using distributive property)

(iii) 7459 × 999 + 7459
= 7459× (999 + 1)
= 7459 × 1000
= 7459000                         (By using distributive property)

(iv) 9870 × 561 − 9870 × 461
= 9870 × (561 − 461)
= 9870 × 100
= 987000                           (By using distributive property)

(v)  569 × 17 + 569 × 13 + 569 × 70
= 569 × (17+ 13+ 70)
= 569  × 100
= 56900                            (By using distributive property)

(vi) 16825 × 16825 − 16825 × 6825
= 16825 × (16825 − 6825)
=  16825 × 10000
= 168250000                        (By using distributive property)

Question 4:

Determine each of the following products by suitable rearrangements:
(i) 2 × 1658 × 50
(ii) 4 × 927 × 25
(iii) 625 × 20 × 8 × 50
(iv) 574 × 625 × 16
(v) 250 × 60 × 50 × 8
(vi) 8 × 125 × 40 × 25

(i) 2 × 1658 × 50
= (2 × 50) × 1658
= 100 × 1658
= 165800

(ii) 4 × 927 × 25
= (4 × 25) × 927
= 100 × 927
= 92700

(iii) 625 × 20 × 8 × 50
= (20  × 50) ×  8 × 625
= 1000 ×  8 × 625
= 8000 × 625
= 5000000

(iv) 574 × 625 × 16
= 574 × (625 × 16)
=  574 × 10000
= 5740000

(v)  250 × 60 × 50 × 8
= (250 × 8) × (60 × 50)
=  2000  × 3000
=  6000000

(vi)  8 × 125 × 40 × 25
=  (8 × 125) × (40 × 25)
= 1000 × 1000
= 1000000

Question 5:

Find each of the following products, using distributive laws:
(i) 740 × 105
(ii) 245 × 1008
(iii) 947 × 96
(iv) 996 × 367
(v) 472 × 1097
(vi) 580 × 64
(vii) 439 × 997
(viii) 1553 × 198

(i)  740 × 105
= 740 × (100 + 5)
= 740 × 100 + 740 × 5                    (Using distributive law of multiplication over addition)
= 74000 + 3700
= 77700

(ii) 245 × 1008
= 245 × (1000 + 8)
= 245 × 1000 + 245 × 8                  (Using distributive law of multiplication over addition)
= 245000 + 1960
= 246960

(iii) 947 × 96
= 947 × ( 100 − 4)
=  947 × 100 − 947 × 4                    (Using distributive law of multiplication over subtraction)
= 94700 − 3788
= 90912

(iv)  996 × 367
=  367 × (1000 − 4)
=   367 × 1000 − 367 × 4             (Using distributive law of multiplication over subtraction)
= 367000 × 1468
= 365532

(v) 472 × 1097
= 472 × ( 1000 + 97)
= 472 × 1000 + 472 × 97                 (Using distributive law of multiplication over addition)
= 472000 + 45784
= 517784

(vi)  580 × 64
=  580 × (60 + 4)
=  580 × 60 + 580 × 4                        (Using distributive law of multiplication over addition)
= 34800 + 2320
= 37120

(vii) 439 × 997
= 439 × (1000 − 3)
= 439 × 1000 − 439 × 3                   (Using distributive law of multiplication over subtraction)
= 439000 − 1317
= 437683

(viii) 1553 × 198
= 1553 × (200 − 2)
= 1553 × 200 − 1553 × 2                 (Using distributive law of multiplication over subtraction)
= 310600 − 3106
= 307494

Question 6:

Find each of the following products, using distributive laws:
(i) 3576 × 9
(ii) 847 × 99
(iii) 2437 × 999

Distributive property of multiplication over addition states that a (b + c) = ab + ac
Distributive property of multiplication over subtraction  states that a (b c) = ab - ac
(i) 3576  ​×  9
= 3576 × (10 − 1)
= 3576 ​× 10 − 3576 × 1
= 35760 − 3576
= 32184

(ii) 847 ×  99
= 847 × (100 − 1)
= 847 × 100 − 847 × 1
=  84700 − 847
= 83853

(iii) 2437 × 999
= 2437 × (1000 − 1)
= 2437 × 1000 − 2437 × 1
=  2437000 − 2437
= 2434563

Question 7:

Find the products:
(i)

(ii)

(iii)

(iv)

(i)

458 × 67 = 30686

(ii)

3709 × 89 = 330101

(iii)

4617 × 234 = 1080378

(iv)

15208 × 542 = 8242736

Question 8:

Find the product of the largest 3-digit number and the largest 5-digit number.

Largest three-digit number = 999
Largest five-digit number = 99999
∴ Product of the two numbers = 999 × 99999
= 999 × (100000 − 1)                  (Using distributive law)
= 99900000 − 999
= 99899001

Question 9:

A car moves at a uniform speed of 75 km per hour. How much distance will it cover in 98 hours?

Uniform speed of a car = 75 km/h

Distance = speed × time
= 75 × 98
=75 × (100 − 2)                     (Using distributive law)
=75 × 100 − 75 × 2
=7500 − 150
= 7350 km

∴ The distance covered in 98 h is 7350 km.

Question 10:

A dealer purchased 139 VCRs. If the cost of each set is Rs 24350, find the cost of all the sets together.

Cost of 1 VCR set = Rs 24350
Cost of 139 VCR sets = 139 × 24350
=24350 × (140 − 1)                 (Using distributive property)
=24350 × 140 − 24350
=3409000 − 24350
= Rs. 3384650

∴ The cost of all the VCR sets is Rs 33,84,650.

Question 11:

A housing society constructed 197 houses. If the cost of construction for each house is Rs 450000, what is the total cost for all the houses?

Cost of construction of 1 house = Rs 450000
Cost of construction of 197 such houses = 197 × 450000
= 450000 × (200 − 3)
= 450000 × 200 − 450000 × 3               [Using distributive property of multiplication over subtraction]
= 90000000 − 1350000
= 88650000

∴ The total cost of construction of 197 houses is Rs 8,86,50,000.

Question 12:

50 chairs and 30 blackboards were purchased for a school. If each chair costs Rs 1065 and each blackboard costs Rs 1645, find the total amount of the bill.

Cost of a chair = Rs 1065
Cost of a blackboard = Rs 1645
Cost of 50 chairs = 50 × 1065 = Rs 53250
Cost of 30 blackboards = 30 × 1645 = Rs 49350
∴ Total amount of the bill = cost of 50 chairs + cost of 30 blackboards
= Rs (53250 + 49350)
= Rs 1,02,600

Question 13:

There are six sections of Class VI in a school and there are 45 students in each section. If the monthly charges from each student be Rs 1650, find the total monthly collection from Class VI.

Number of student in 1 section = 45
Number of students in 6 sections = 45 × 6 = 270
Monthly charges from 1 student = Rs 1650
∴ Total monthly collection from class VI = Rs 1650 × 270 = Rs 4,45,500

Question 14:

The product of two whole numbers is zero. What do you conclude?

If the product of two whole numbers is zero, then one of them is definitely zero.
Example: 0 × 2 = 0 and 0 × 15 = 0

If the product of whole numbers is zero, then both of them may be zero.
i.e., 0 × 0 = 0

Now, 2 × 5 = 10. Here, the product will be non-zero because the numbers to be multiplied are not equal to zero.

Question 15:

Fill in the blanks:
(i) Sum of two odd numbers is an ...... number.
(ii) Product of two odd numbers is an ...... number.
(iii) and a × a = a $⇒$ a = ?

(i) Sum of two odd numbers is an even number. Example: 3 + 5 = 8, which is an even number.
(ii) Product of two odd numbers is an odd number. Example: 5 × 7 = 35, which is an odd number.
(iii)  ≠ 0 and a × a = a
Given: a × a = a
⇒ a = $\frac{a}{a}=1$
, ≠ 0

Question 1:

Divide and check your answer by the corresponding multiplication in each of the following:
(i) ​1936 ​÷ 36
(ii) 19881 ​÷ 47
(iii) 257796 ​÷ 341
(iv) 612846 ​÷ 582
(v) 34419 ​÷ 149
(vi) 39039 ​
÷ 1001

(i)

Dividend = 1936, Divisor = 36 , Quotient = 53 , Remainder = 28
Check: Divisor × Quotient + Remainder  =  36 × 53 + 28
= 1936
=Dividend
Hence, Dividend = Divisor × Quotient + Remainder
Verified.
(ii) 19881 ​÷ 47

Dividend = 19881, Divisor = 47 , Quotient = 423, Remainder = 0
Check: Divisor ×Quotient + Remainder= 47 × 423 + 0
= 19881
=Dividend
Hence, Dividend = Divisor × Quotient + Remainder
Verified.

(iii)

Dividend = 257796 , Divisor = 341 , Quotient = 756 , Remainder = 0
Check : Divisor × Quotient + Remainder = 341 × 756 + 0
= 257796
= Dividend
Hence, Dividend = Divisor × Quotient + Remainder
Verified.

(iv) 612846 ​÷ 582

Dividend = 612846 , Divisor = 582, Quotient = 1053 , Remainder = 0
Check :  Divisor × Quotient + Remainder= 582 × 1053 + 0
= 612846
=Dividend
Hence, Dividend = Divisor × Quotient + Remainder
Verified.

(v) 34419 ​÷ 149

Dividend = 34419, Divisor = 149 , Quotient = 231, Remainder = 0
Check : Divisor × Quotient + Remainder  = 149 × 231 + 0
= 34419
=Dividend
Hence, Dividend = Divisor × Quotient + Remainder
Verified.

(vi) 39039 ​÷ 1001

Dividend = 39039 , Divisor = 1001 , Quotient = 39 , Remainder = 0
Check : Divisor × Quotient + Remainder = 1001 × 39 + 0
= 39039
=Dividend
Hence, Dividend = Divisor × Quotient + Remainder
Verified.

Question 2:

(i) 6971 ​÷ 47
(ii) 4178 ​÷ 35
(iii) 36195 ​÷ 153
(iv) 93575 ​÷ 400
(v) 23025 ​÷ 1000
(vi) 16135 ​
÷ 875

(i)  6971 ​÷ 47

Quotient = 148 and Remainder = 15
Check: Divisor × Quotient + Remainder = 47 × 148 + 15
= 6971
= Dividend
∴ Dividend = Divisor × Quotient + Remainder
Verified.

(ii)  4178 ​÷ 35

Dividend = 119 and Remainder = 13
Check: Divisor × Quotient + remainder = 35 ×  119 + 13
= 4178
= Dividend

∴ Dividend= Divisor × Quotient + Remainder
Verified.
(iii) 36195 ​÷ 153

Quotient = 236 and Remainder = 87
Check: Divisor × Quotient + Remainder =  153 × 236 + 87
= 36195
= Dividend
∴ Dividend= Divisor × Quotient +Remainder
Verified.
(iv) 93575 ​÷ 400

Quotient = 233 and Remainder = 375
Check: Divisor × Quotient + Remainder =  400 ×  233 + 375
= 93575
= Dividend
∴ Dividend= Divisor × Quotient + Remainder
Verified.

(v)  23025 ​÷ 1000

Quotient = 23 and remainder = 25
Check: Divisor × Quotient + Remainder =1000  × 23 + 25
= 23025
= Dividend
∴ Dividend= Divisor × Quotient +Remainder
Verified.
(vi) 16135 ​÷ 875

Quotient = 18 and Remainder = 385
Check: Divisor × Quotient + Remainder =875  ×  18 + 385
= 16135
= Dividend
∴ Dividend= Divisor × Quotient +Remainder
Verified.

Question 3:

Find the value of
(i) 65007 ​÷ 1
(ii) 0 ​÷ 879
(iii) 981 + 5720 ​÷ 10
(iv) 1507 − (625 ÷ 25)
(v) 32277 ÷ (648 − 39)
(vi) (1573 ÷ 1573) − (1573 ÷ 1573)

(i) 65007 ​÷ 1 = 65007

(ii) 0 ​÷ 879  = 0

(iii) 981 + 5720 ​÷ 10
= 981 + (5720 ​÷ 10)                               (Following DMAS property)
= 981 + 572
= 1553

(iv) 1507 − (625 ÷ 25)                             (Following BODMAS property)
= ​​1507 − 25
= 1482

(v) 32277 ÷ (648 − 39)                                 (Following BODMAS property)
= ​32277 ÷ (609)
=  53

(vi)  (1573 ÷ 1573) − (1573 ÷ 1573)            (Following BODMAS property)
= 1 − 1
= 0

Question 4:

Find a whole number n such that n ÷ n = n.

Given:  n ÷ = n
⇒  $\frac{n}{n}$= n
​⇒  n = n2

i.e., the whole number n is equal to n2.

∴ The given whole number must be 1.

Question 5:

The product of two numbers is 504347. If one of the numbers is 317, find the other.

Let x and y be the two numbers.

Product of the two numbers = x × y = 504347

If x = 317, we have:

317 × y = 504347
⇒ y = 504347 ÷ 317

y=  1591

∴ The other number is 1591.

Question 6:

On dividing 59761 by a certain number, the quotient is 189 and the remainder is 37. Find the divisor.

Dividend = 59761, quotient = 189, remainder = 37 and divisor = ?

Dividend = divisor × quotient + remainder
⇒ 59761 = divisor × 189 + 37
⇒ 59761 − 37 = divisor × 189
⇒ 59724 = divisor × 189
⇒ Divisor = 59724 ​÷ 189

Hence, divisor =316

Question 7:

On dividing 55390 by 299, the remainder is 75. Find the quotient using the division algorethm.

Here, Dividend = 55390, Divisor = 299 and Remainder = 75
We have to find the quotient.
Now, Dividend = Divisor × Quotient + Remainder
⇒ 55390 = 299 × Quotient + 75
⇒ 55390 − 75 = 299 × Quotient
⇒ 55315 = 299 × Quotient
⇒ Quotient = 55315 ​÷ 299

Hence, quotient =185

Question 8:

What least number must be subtracted from 13601 to get a number exactly divisible by 87?

First, we will divide 13601 by 87.

Remainder = 29
So, 29 must be subtracted from 13601 to get a number exactly divisible by 87.
i.e., 13601 − 29 = 13572

Now, we have:

∴ 29 must be subtracted from 13601 to make it divisible by 87.

Question 9:

What least number must be added to 1056 to get a number exactly divisible by 23?

First, we will divide 1056 by 23.

Required number = 23 − 21 = 2
So, 2 must be added to 1056 to make it exactly divisible by 23.
i.e., 1056 + 2 = 1058

Now, we have:

∴ 1058 is exactly divisible by 23.

Question 10:

Find the largest 4-digit number divisible by 16.

We have to find the largest four digit number divisible by 16 .
The largest four-digit number = 9999
Therefore, dividend =9999
Divisor =16

Here, we get remainder =15
Therefore, 15 must be subtracted from 9999 to get the largest four digit number that is divisible by 16.
i.e., 9999 − 15 = 9984

Thus, 9984 is the largest four-digit number that is divisible by 16.

Question 11:

Divide the largest 5 digit number by 653. Check your answer by the division algorithm.

Largest five-digit number =99999

Dividend = 99999, Divisor = 653, Quotient = 153 and Remainder = 90
Check: Divisor ×Quotient + Remainder
= 653 × 153 + 90
= 99909 + 90
= 99999
= Dividend

∴ Dividend = Divisor × Quotient + Remainder
Verified.

Question 12:

Find the least 6-digit number exactly divisible by 83.

Least six-digit number = 100000
Here, dividend = 100000 and divisor = 83

In order to find the least 6-digit number exactly divisible by 83, we have to add 83 − 68 = 15 to the dividend.
I.e., 100000 + 15 = 100015

So, 100015 is the least six-digit number exactly divisible by 83.

Question 13:

1 dozen bananas cost Rs 29. How many dozens can be purchased for Rs 1392?

Cost of 1 dozen bananas = Rs 29
Number of dozens purchased for Rs 1392 = 1392 ÷ 29

Hence, 48 dozen of bananas can be purchased with Rs. 1392.

Question 14:

19625 trees have been equally planted in 157 rows. Find the number of trees in each row.

Number of trees planted in 157 rows = 19625
Trees planted in 1 row = 19625 ÷ 157

∴ 125 trees are planted in each row.

Question 15:

The population of a town is 517530. If one out of every 15 is reported to be literate, find how many literate persons are there in the town.

Population of the town = 517530
$\left(\frac{1}{15}\right)$ of the population is reported to be literate, i.e., $\left(\frac{1}{15}\right)$ × 517530 = 517530 $÷$ 15

∴ There are 34502 illiterate persons in the given town.

Question 16:

The cost price of 23 colour television sets is Rs 570055. Determine the cost price of each TV set if each costs the same.

Cost price of 23 colour TV sets = Rs 5,70,055
Cost price of 1 TV set  = Rs 570055 ÷ 23

∴ The cost price of one TV set is Rs 24,785.

Question 1:

The smallest whole number is
(a) 1
(b) 0
(c) 2
(d) none of these

(b) 0

The smallest whole number is 0.

Question 2:

The least number of 4 digits which is exactly divisible by 9 is
(a) 1018
(b) 1026
(c) 1009
(d) 1008

(d) 1008

(a)

Hence, 1018 is not exactly divisible by 9.

(b)

Hence, 1026 is exactly divisible by 9.
(c)

Hence, 1009 is not exactly divisible by 9.

(d)

Hence, 1008 is exactly divisible by 9.

(b) and (d) are exactly divisible by 9, but (d) is the least number which is exactly divisible by 9.

Question 3:

The largest number of 6 digits which is exactly divisible by 16 is
(a) 999980
(b) 999982
(c) 999984
(d) 999964

(c) 999984

(a)

Hence, 999980 is not exactly divisible by 16.
(b)

Hence, 999982 is not exactly divisible by 16.
(c)

Hence, 999984 is exactly divisible by 16.
(d)

Hence, 999964 is not exactly divisible by 16.

The largest six-digit number which is exactly divisible by 16 is 999984.

Question 4:

What least number should be subtracted from 10004 to get a number exactly divisible by 12?
(a) 4
(b) 6
(c) 8
(d) 20

(c) 8

Here we have to tell what least number should be subtracted from 10004 to get a number exactly divisible by 12
So, we will first divide 10004 by 12.

Remainder = 8
So, 8 should be subtracted from 10004 to get the number exactly divisible by 12.
i.e., 10004 − 8 = 9996

Hence, 9996 is exactly divisible by 12.

Question 5:

What least number should be added to 10056 to get a number exactly divisible by 23?
(a) 5
(b) 18
(c) 13
(d) 10

(a) 18

Here , we have to tell that what least number must be added to 10056 to get a number exactly divisible by 23
So, first we will divide 10056 by 23

Remainder = 5
Required number = 23 − 5 = 18

So, 18 must be added to 10056 to get a number exactly divisible by 23.
i.e., 10056 + 18 = 10074

Hence, 10074 is exactly divisible by 23 .

Question 6:

What whole number is nearest to 457 which is divisible by 11?
(a) 450
(b) 451
(c) 460
(d) 462

(d) 462

(a)

Hence, 450 is not divisible by 11.
(b)

Hence, 451 is divisible by 11.
(c)

Hence, 460 is not divisible by 11.
(d)

Hence, 462 is divisible by 11.

Here, the numbers given in options (b) and (d) are divisible by 11. However, we want a whole number nearest to 457 which is divisible by 11.
So, 462 is whole number nearest to 457 and divisible by 11.

Question 7:

How many whole numbers are there between 1018 and 1203?
(a) 185
(b) 186
(c) 184
(d) none of these

(c) 184

Number of whole numbers = (1203 − 1018) − 1
= 185 − 1
=  184

Question 8:

A number when divided by 46 gives 11 as quotient and 15 as remainder. The number is
(a) 491
(b) 521
(c) 701
(d) 679

(b) 521

Divisor = 46
Quotient = 11
Remainder = 15
Dividend = divisor × quotient + remainder
= 46 × 11 + 15
= 506 + 15
= 521

Question 9:

In a division sum, we have dividend = 199, quotient = 16 and remainder = 7. The divisor is
(a) 11
(b) 23
(c) 12
(d) none of these

(c) 12

Dividend = 199
Quotient = 16
Remainder = 7
According to the division algorithm, we have:
Dividend = divisor × quotient + remainder
⇒ 199 = divisor × 16 + 7
⇒ 199 − 7 = divisor × 16
⇒ Divisor = 192 ÷ 16

Question 10:

7589 − ? = 3434
(a) 11023
(b) 4245
(c) 4155
(d) none of these

(a) 11023

7589 − ? = 3434
⇒ 7589 − x = 3434
x = 7589 + 3434
x = 11023

Question 11:

587 × 99 = ?
(a) 57213
(b) 58513
(c) 58113
(d) 56413

(c) 58113

587 × 99
= 587 × (100 − 1)
= 587 × 100 − 587 × 1         [Using distributive property of multiplication over subtraction]
= 58700 − 587
= 58113

4 × 538 × 25 = ?
(a) 32280
(b) 26900
(c) 53800
(d) 10760

(c) 53800

4 × 538 × 25
= (4 × 25) × 538
=  100 × 538
= 53800

Question 13:

24679 × 92 + 24679 × 8 = ?
(a) 493580
(b) 1233950
(c) 2467900
(d) none of these

(c) 2467900

By using the distributive property, we have:
24679 × 92 + 24679 × 8
= 24679 ×  (92 + 8)
= 24679 × 100
= 2467900

Question 14:

1625 × 1625 − 1625 × 625 = ?
(a) 1625000
(b) 162500
(c) 325000
(d) 812500

(a) 1625000

By using the distributive property, we have:

1625 × 1625 − 1625 × 625
= 1625 × (1625 − 625)
=1625 × 1000
= 1625000

Question 15:

1568 × 185 − 1568 × 85 = ?
(a) 7840
(b) 15680
(c) 156800
(d) none of these

(c) 156800

By using the distributive property, we have:
1568 × 185 − 1568 × 85
= 1568 × (185 − 85)
= 1568 × 100
= 156800

Question 16:

(888 + 777 + 555) = (111 × ?)
(a) 120
(b) 280
(c) 20
(d) 140

(c) 20

(888 + 777 + 555) = (111 × ?)
⇒ (888 + 777 + 555) = 111 × (8 + 7 + 5)          [By taking 111 common]
= ​111 × (20) = 2220

Question 17:

The sum of two odd numbers is
(a) an odd number
(b) an even number
(c) a prime number
(d) a multiple of 3

(b) an even number

The sum of two odd numbers is an even number.

Example: 5 + 3 = 8

Question 18:

The product of two odd numbers is
(a) an odd number
(b) an even number
(c) a prime number
(d) none of these

(a) an odd number

The product of two odd numbers is an odd number.

Example: 5 × 3 = 15

Question 19:

If a is a whole number such that a + a = a, then a = ?
(a) 1
(b) 2
(c) 3
(d) none of these

(d) none of these

Given: a is a whole number such that a + a = a.

If a = 1, then 1+ 1 = 2 ≠ 1
If a =2, then 2 + 2 = 4 ≠ 2
If a =3, then 3 + 3 = 6 ≠ 3

Question 20:

The predecessor of 10000 is
(a) 10001
(b) 9999
(c) none of these

(b) 9999

Predecessor of 10000 = 10000 − 1 = 9999

Question 21:

The successor of 1001 is
(a) 1000
(b) 1002
(c) none of these

(b) 1002

Successor of 1001 = 1001 + 1 = 1002

Question 22:

The smallest even whole number is
(a) 0
(b) 2
(c) none of these

(b) 2

The smallest even whole number is 2. Zero (0) is neither an even number nor an odd number.

Question 1:

How many whole numbers are there between 1064 and 1201?

Number of whole numbers between 1201 and 1064 = ( 1201 − 1064 ) − 1
= 137 − 1
= 136

Question 2:

Fill in the blanks.

1000000
−      ****1

*7042*

Then, we have:

1000000
−    29571

970429

Question 3:

Use distributive law to find the value of

1063 × 128 − 1063 × 28.

Using distributive law, we have:
1063 × 128 − 1063 × 28
= 1063 × (128 − 28)
= 1063 × 100
= 106300

Question 4:

Find the product of the largest 5-digit number and the largest 3-digit number using distributive law.

Largest five-digit number = 99999
Largest three-digit number = 999

By using distributive law, we have:

Product = 99999 × 999
= 99999 × (1000 − 1)                                  [By using distributive law]
= 99999 × 1000 −  99999 × 1
= 99999000 − 99999
= 99899001

OR

999 × 99999
= 999 × ( 100000 − 1)                                   [By using distributive law]
= 999 × 100000 − 999 × 1
= 99900000 − 999
= 99899001

Question 5:

Divide 53968 by 267 and check the result by the division algorithm.

Dividend = 53968, Divisor = 267, Quotient = 202 and Remainder = 34

Check: Quotient × Divisor + Remainder
= 267  × 202 + 34
=  53934 + 34
= 53968
= Dividend

∴ Dividend = Quotient × Divisor + Remainder

Verified.

Question 6:

Find the largest 6-digit number divisible by 16.

Largest six-digit number = 999999

Remainder = 15

Largest six-digit number divisible by 16 = 999999 − 15 = 999984

∴ 999984 is divisible by 16.

Question 7:

The cost price of 23 TV sets is Rs 570055. Find the cost of each such set.

Cost price of 23 TV sets = Rs 5,70,055
Cost price of 1 TV set = 570055 ÷ 23

∴ The cost of one TV set is Rs 24,785.

Question 8:

What least number must be subtracted from 13801 to get a number exactly divisible by 87?

We have to find the least number that must be subtracted from 13801 to get a number exactly divisible by 87
So, first we will divide 13801 by 87

Remainder = 55
The number 55 should be subtracted from 13801 to get a number divisible by 87.
i.e., 13801 − 55 = 13746

∴ 13746 is divisible by 87.

Question 9:

The value of (89 × 76 + 89 × 24) is
(a) 890
(b) 8900
(c) 89000
(d) 10420

(b) 8900

(89 × 76 + 89 × 24)
= 89 × (76 + 24)       [Using distributive property of multiplication over addition]
= 89 × 100
= 8900

Question 10:

On dividing a number by 53 we get 8 as quotient and 5 as remainder. The number is
(a) 419
(b) 423
(c) 429
(d) none of these

(c) 429

Divisor = 53, Quotient = 8, Remainder = 5 and Dividend = ?

Now, Dividend = Quotient × Divisor +Remainder
= 8 × 53 + 5
= 429

Question 11:

The whole number which has no predecessor is
(a) 1
(b) 0
(c) 2
(d) none of these

(b) 0

The whole number which has no predecessor is 0.

i.e., 0 − 1 = −1, which is not a whole number.

Question 12:

67 + 33 = 33 + 67 is an example of
(a) closure property
(b) associative property
(c) commutative property
(d) distributive property

(c) Commutative property

67 + 33 = 33 + 67 is an example of​ commutative property of addition.

Question 13:

(a) $\frac{1}{36}$
(b) 0
(c) −36
(d) none of these

(c) -36
The additive inverse of 36 is −36.

i.e., 36 + (−36) = 0

Question 14:

Which of the following is not zero?
(a) 0 × 0
(b) $\frac{0}{2}$
(c)
(d) 2 + 0

(d) 2+0

(a) 0 × 0 = 0
(b) 0/2 = 0
(c) $\frac{\left(8-8\right)}{2}=\frac{0}{2}$ =0
(d) 2 + 0 = 2

Question 15:

The predecessor of the smallest 3-digit number is
(a) 999
(b) 100
(c) 101
(d) 99

(d) 99

Smallest three-digit number = 100
∴ Predecessor of 100 = 100 − 1 = 99

Question 16:

The number of whole numbers between the smallest whole number and the greatest 2-digit number is
(a) 88
(b) 98
(c) 99
(d) 101

(b) 98
Smallest whole number = 0
Greatest two-digit number = 99
Number of whole numbers between 0 and 99 = (99 − 0 ) − 1 = 98

Question 17:

Fill in the blanks.
(i) The smallest natural number is ...... .
(ii) The smallest whole number is ...... .
(iii) Division by ...... is not defined.
(iv) ...... is a whole number which is not a natural number.
(v)...... is a whole number which is not a natural number.

(i) The smallest natural number is 1.
(ii) The smallest whole number is 0.
(iii) Division by 0 is not defined.
(iv) 0 is a whole number which is not a natural number.
(v) 1 is the multiplicative identity for whole numbers.

Question 18:

Write 'T' for true and 'F' for false in each of the following:
(i) 0 is the smallest natural number.
(ii) Every natural number is a whole number.
(iii) Every whole number is a natural number.
(iv) 1 has no predecessor in whole numbers.

(i)  F (false). 0 is not a natural number.
​(ii) T (true).
(iii) F (false). 0 is a whole number but not a natural number.
(iv) F (false). 1 − 1 = 0 is a predecessor of 1, which is a whole number.

Question 19:

Match the following columns on whole numbers:

 column A column B (a) 137 + 63 = 63 + 137 (i) Associativity of multiplication (b) (16 × 25) is a number (ii) Commutativity of multiplication (c) 365 × 18 = 18 × 365 (iii) Distributive law of multiplication over addition (d) (86 × 14) × 25 = 86 × (14 × 25) (iv) Commutativity of addition (e) 23 × (80 + 5) = (23 × 80) + (23 × 5) (v) Closure property for multiplication