Q1: Estimate the following by rounding off each factor to nearest hundreds:
(i) 730 + 998
(ii) 796 – 314
(iii) 875 – 384
Ans:
(i) It can be rounded off to the nearest hundreds as 700 + 1000 = 1, 700.
(ii) It can be rounded off to the nearest hundreds as 800 – 300 = 500.
(iii) It can be rounded off to the nearest hundreds as 900 – 400 = 500.
Q2: Estimate the following by rounding off each factor to nearest thousands:
(i) 12, 094 + 2, 888
(ii) 28, 292 – 21, 496
Ans:
(i) It can be rounded off to the nearest thousands as 13, 000 + 3, 000 = 16, 000.
(ii) It can be rounded off to the nearest thousands as 28, 000 – 21, 000 = 7, 000.
Q3: Estimate the following by rounding off each number to its greatest place:
(i) 439 + 334 + 4, 317
(ii) 8, 325 – 491
(iii) 1, 08, 734 – 47, 599
(iv) 898 × 785
(v) 9 × 795
(vi) 87 × 317
Ans:
(i) It can be rounded off to its greatest place as 400 + 300 + 4, 000 = 4, 700.
(ii) It can be rounded off to its greatest place as 8, 000 – 500 = 7, 500.
(iii) It can be rounded off to its greatest place as 1, 00, 000 – 50, 000 = 50, 000.
(iv) It can be rounded off to its greatest place as 900 × 800 = 7, 20, 000.
(v) It can be rounded off to its greatest place as 10 × 800 = 8, 000.
(vi) It can be rounded off to its greatest place as 90 × 300 = 27, 000.
Q4: Find the estimated quotient for each of the following by rounding off each number to its greatest place:
(i) 878 ÷ 28
(ii) 745 ÷ 24
(iii) 4489 ÷ 394
Ans:
(i) It can be rounded off to its greatest place as 900 ÷ 30 = 30.
(ii) It can be rounded off to its greatest place as 700 ÷ 20 = 35.
(iii) It can be rounded off to its greatest place as 4000 ÷ 400 = 10.
