Page 104 - ICSE Math 4

• When we subtract two same frac ons, we get 0 as the result.
3 3 13 13
For example, – = 0 and – = 0.
11 11 21 21
Word Problems
1 3
Example 6: Mrs Jha bought kg of sugar and Mrs Dua bought kg of sugar. Find the
2 2
total amount of sugar bought by them. Write the frac on in the lowest
term.

1 3
Solu on: Sugar bought by Mrs Jha = kg; Sugar bought by Mrs Dua = kg
2 2
1 3 1 3 1 + 3 4
Total quan ty of sugar bought = kg + kg = + kg = kg = kg = 2 kg
2 2 2 2 2 2
So, they bought 2 kg of sugar.

Example 7: Maya weighed two pieces of metal for an experiment. The fi rst piece of
5 1
metal weighed g and the second piece of metal weighed g. What is the
6 6
diff erence between the weights of these two pieces of metal?

5 1
Solu on: Weight of the fi rst metal = g; Weight of the second metal = g
6 6
5 1
 Weight of second metal less than the fi rst metal = g – g
6 6
5 1 5 – 1 4 2
= – g = g = g = g
6 6 6 6 3
2
So, the weight of the second metal is g less than the weight of the fi rst
3
metal.

Exercise 8.5

1. Add the following frac ons.
3 1 4 3 2 4
(a) + (b) + (c) +
4 4 10 10 7 7
5 2 3 13 7 1 3 6 2
(d) + + (e) + + (f) + +
11 11 11 28 28 28 15 15 15

2. Subtract the following frac ons.

24 13 9 5 13 11
(a) – (b) – (c) –
27 27 16 16 22 22
14 7 12 2 14 13
(d) – (e) – (f) –
25 25 19 19 26 26

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