Percentage ↔ Fraction

Turn awkward percentages into simple fractions to calculate in your head.

25% = 1/4 · 12.5% = 1/8 · 33⅓% = 1/3 · 16⅔% = 1/6

1How it works

Many percentages map to clean fractions. Multiplying by a fraction is far faster than multiplying by a decimal, so memorising the common ones lets you solve percentage MCQs almost instantly.

2How to apply (in seconds)

Recall the fraction for the given percentage (e.g. 37.5% = 3/8).
Multiply the number by that fraction.
Cancel and simplify to get the answer.

3Worked examples

Example 1 Worked solution

Q. Find 37.5% of 56.

37.5% = 3/8.
56 × 3/8 = (56 ÷ 8) × 3.
= 7 × 3.

✓ 21

Example 2 Worked solution

Q. Find 16⅔% of 90.

16⅔% = 1/6.
90 × 1/6 = 90 ÷ 6.

✓ 15

4When to use it

✦Any “percentage of a number” MCQ.
✦Data interpretation, where speed matters most.
✦Profit-loss and discount sums.

5Cautions & tips

!Memorise the table up to 1/12 (about 8⅓%).
!Divide first, then multiply, to keep the numbers small.