Card 3 of 8
Fractions, decimals & percentages
The equivalence table worth knowing on sight, plus the conversion rules.
The single most useful table on this page. Learn every row both directions.
| Fraction | Decimal | Percentage |
|---|---|---|
| 1/2 | 0.5 | 50% |
| 1/3 | 0.333… | 33⅓% |
| 2/3 | 0.666… | 66⅔% |
| 1/4 | 0.25 | 25% |
| 3/4 | 0.75 | 75% |
| 1/5 | 0.2 | 20% |
| 2/5 | 0.4 | 40% |
| 3/5 | 0.6 | 60% |
| 4/5 | 0.8 | 80% |
| 1/8 | 0.125 | 12.5% |
| 3/8 | 0.375 | 37.5% |
| 5/8 | 0.625 | 62.5% |
| 7/8 | 0.875 | 87.5% |
| 1/10 | 0.1 | 10% |
| 3/10 | 0.3 | 30% |
| 7/10 | 0.7 | 70% |
| 9/10 | 0.9 | 90% |
| 1/100 | 0.01 | 1% |
Converting, in one line each:
- Fraction → decimal: divide top by bottom (3 ÷ 8 = 0.375)
- Decimal → percentage: × 100 (0.375 → 37.5%)
- Percentage → fraction: over 100, then simplify (45% = 45/100 = 9/20)
- Decimal → fraction: say it aloud — "nought point four five" = 45 hundredths = 45/100 = 9/20
Percentages by building from 10% (faster than long multiplication in an exam):
35% of 240 → 10% = 24 → 30% = 72 → 5% = 12 → 84