Page 76 - Maths Class 05

4 , 7 1
Example : Convert 1, and into like fractions.
5 10 2

Solution : Find the LCM of the denominators.

LCM of 1, 5, 10 and 2 is 10.

Calculate their equivalent fractions with the same denominator, that is,
the LCM.

1 1 × 10 10 4 4 × 2 8
= = ; = =
1 1 × 10 10 5 5 × 2 10

7 7 × 1 7 1 1 × 5 5
= = ; = =
10 10 × 1 10 2 2 × 5 10

4 7 1
1, , and which are unlike fractions can be represented as
5 10 2

10 8 7 5
, , and which are like fractions.
10 10 10 10

Writing a Fraction in its Simplest Form

A fraction is in its simplest form when its numerator and denominator have no highest

common factors other than 1.

1 2 3 1
,
,
,
Fractions such as are all in their simplest form. In there is no common
2 5 8 2
2
factor of 1 and 2 except 1. Likewise, the only common factor of 2 and 5 in is 1 and 3
5
3
and 8 in is 1.
8
10
The fraction is not in its simplest form because 5 is the HCF of 10 and 15.
15

6
Similarly, is not in its lowest form because 3 is the HCF of 6 and 21.
21

For writing fractions in their simplest form, there are two rules to follow :

Ÿ Ask if the numerator and denominator can be divided by the same number, which is
the HCF of the numerator and denominator.

Ÿ See if at least one number in the fraction is a prime number.

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