RS Aggarwal Solutions: Number System (Exercise 1F)

Solution 1:
87 ÷ 28
87 is estimated to the nearest ten = 90
28 is estimated to the nearest ten = 30
∴ 90 ÷ 30 = 3

Solution 2:
83 ÷ 17
83 is estimated to the nearest ten = 80
17 is estimated to the nearest ten = 20
∴ 80 ÷ 20 = 4

Solution 3:
75 ÷ 23
75 is estimated to the nearest ten = 80
23 is estimated to the nearest ten = 20
∴ 80 ÷ 20 = 4

Solution 4:
193 ÷ 24
193 is estimated to the nearest ten = 190
24 is estimated to the nearest ten = 20
∴ 190 ÷ 20 = 9.5
Estimated quotient is 10

Solution 5:
725 ÷ 23
725 is estimated to the nearest hundred = 700
23 is estimated to the nearest ten = 20
∴ 700 ÷ 20 = 35

Solution 6:
275 ÷ 25
275 is estimated to the nearest hundred = 300
25 is estimated to the nearest ten = 30
∴ 300 ÷ 30 = 10

Solution 7:
633 ÷ 33
633 is estimated to the nearest hundred = 600
33 is estimated to the nearest ten = 30
∴ 600 ÷ 30 = 20

Solution 8:
729 ÷ 29
729 is estimated to the nearest hundred = 700
29 is estimated to the nearest ten = 30
∴ 700 ÷ 30
= 70 ÷ 3
= 23 (approximately)

Solution 9:
858 ÷ 39
858 is estimated to the nearest hundred = 900
39 is estimated to the nearest ten = 40
∴ 900 ÷ 40
= 90 ÷ 4
= 23 (approximately)

Solution 10:
868 ÷ 38
868 is estimated to the nearest hundred = 900 
38 is estimated to the nearest ten = 40
∴ 900 ÷ 40
= 90 ÷ 4
= 23 (approximately)