Page 103 - ICSE Math 4

Properties of Addition of Fractions
Mental Maths
• Two or more frac ons can be added in any order.
1 2 2 1 Fill in the boxes.
For example, + = + 3 6
4 4 4 4 (a) + =
1 2 1 + 2 3 2 1 2 + 1 3 7 7 7
+ = = and + = = .
4 4 4 4 4 4 4 4 (b) 1 3 4
+ =
Since the two frac ons give the same result on 8 8
addi on, they can be added in any order.

• When 0 is added to any frac on, we get the same frac on as the sum.
7 7 7 7
For example, + 0 = or 0 + = .
11 11 11 11
Subtraction of Like Fractions

Look at the fi gure given alongside, there are 2 coloured
parts out of 5 total parts.
2 2
So, the frac on for the coloured part is . 5
5
If we cut and remove a coloured part from it, then the frac on for the removed part will
1
be .
5

2 1 2 – 1 1
Frac on of the remaining coloured part = – = =
5 5 5 5
So, we can say that only 1 coloured part is le in the fi gure out of 5 total parts.

In other words, we can say that to subtract like frac ons, we subtract the numerators and
keep the denominator as it is.

3 5 35 14
Example 4: Subtract from . Example 5: Fill in the box: – =
7 7 41 41 41

5 3 5 – 3 2 35 – 14
Solu on: – = = Solu on: = or, 35 – = 14
7 7 7 7 41 41

35 – 11 = 14 (since 11 + 14 = 35)
35 11 14
 – =
41 41 41

Properties of Subtraction of Fractions

• When 0 is subtracted from a frac on, we get the same frac on as the diff erence.
8 8
For example, – 0 = .
15 15

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