Card 1 of 10 · Percentages
How do I find 12.5%, 16.67% or 37.5% of a number without a calculator?
Say this first
Memorise the fraction hiding behind the percentage, then divide instead of multiplying.
Picture it
| Fraction | Percent | Example: of 720 |
|---|---|---|
| 1/2 | 50% | 360 |
| 1/3 | 33.33% | 240 |
| 1/4 | 25% | 180 |
| 1/5 | 20% | 144 |
| 1/6 | 16.67% | 120 |
| 1/8 | 12.5% | 90 |
| 1/9 | 11.11% | 80 |
| 1/12 | 8.33% | 60 |
| 3/8 | 37.5% | 270 |
Learn these nine once and half of all percentage questions become one division.
Try it
What is 37.5% of 880?
Common trap
Converting everything to decimals and multiplying under time pressure. 16.67% of 480 is slow by hand; 480 ÷ 6 takes two seconds.
Say it like this
A percentage is a fraction in disguise. Spot the fraction, divide, done.