How to Pass Numerical Reasoning (10 page)

Reducing a fraction to its lowest terms

In numerical reasoning tests, you will typically see fractions in the lowest terms. There are two methods to reduce a fraction to its lowest terms.

Method 1

Continue to divide the numerator and denominator by common factors until neither the numerator nor denominator can be factored any further.

Worked example

Reduce
to its lowest terms

36 and 90 have a common factor of 18, so divide the numerator and denominator by 18.

Method 2

Use the prime factors to reduce a fraction to its lowest terms. This is a useful technique to use when the numbers are large.

Worked example

Reduce
to its lowest terms.

Factor out the numerator and the denominator:

Now cancel out common factors:

Reducing fractions: practice drill