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.