Page 45 - Viva

Exercise 3.3

1. Subtract the following using the expanded form.

(a) 546 from 930 (b) 772 from 893
(c) 238 from 426 (d) 270 from 540

(e) 169 from 215 (f) 215 from 364

2. Subtract the following using estimation method by rounding off each number to
the nearest 100 and compare with the actual value.

(a) 648 from 935 (b) 772 from 893

(c) 340 from 448 (d) 726 from 892
(e) 278 from 355 (f) 821 from 928

3. Find the difference between 928 and 886 using estimation method by rounding
off the numbers to the nearest 10 and compare with the actual value.

Word Problems

Let’s look at the following examples.

Example 10: There are 927 workers in a factory. Yesterday, 214 of them were on leave.
How many workers were working in the factory yesterday?

Solution: Number of workers in the factory = 927
Number of workers on leave = 214
9 2 7
Number of workers working in the factory = 927 – 214
– 2 1 4
= 713 7 1 3

So, 713 workers were working in the factory yesterday.

Example 11: Vansh is travelling from one city to another by car. The distance between the
two cities is 210 km. If Vansh has crossed 153 km, how much distance is still
left to be covered?

Solution: Total distance between Delhi and Agra = 210 km

Distance covered by Vansh = 153 km 1 10 10
Distance left to be covered by Vansh = (210 – 153) km 2 1 0 km
– 1 5 3 km
= 57 km
0 5 7 km
So, Vansh still has to cover a distance of 57 km.

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