Simplifying fractions
In a nutshell
To simplify a fraction, you reduce the fraction to its lowest form. The lowest form of a fraction occurs when the numerator (top number) and denominator (bottom number) have no common factors except 1.
Example 1
Below are some examples of fractions in their lowest form.
31,92,2013
Simplifying fractions
The quickest way to simplify a fraction is to divide by the highest common factor (HCF). The highest common factor is the largest factor that the numerator and denominator have in common.
Procedure
1. | Determine the HCF of the numerator and the denominator. |
2. | Divide both the numerator and the denominator by the HCF. The resulting fraction is in its simplest form. |
Example 2
Give the fraction 2012 in its simplest form.
List the factors of the numerator and the denominator:
Numerator: 1,2,3,4,6,12
Denominator: 1,2,4,5,10,20
Identify the largest number that appears on both lists:
4
Divide the numerator and denominator by the HCF:
20÷412÷4=53
Tip: If the numerator and denominator are even, you can always divide by 2.
Expanding fractions
To add, subtract or compare fractions the denominators need to be the same.
procedure
1. | Identify the multiplier needed to give both fractions a common denominator. |
2. | Multiply the numerator and denominator by the answer found in Step 1. |
Example 3
Which fraction is greater, 43 or 87?
Identify the multiplier needed to give each fraction a common denominator:
4×2=8
Multiply the numerator and denominator by the multiplier:
4×23×2=86
Compare the two fractions:
86<87 therefore 43<87