Fractions
Fractions as Decimals and Percents
Updated October 2, 2026
To turn a fraction into a decimal, divide the top by the bottom. Multiply by 100 for the percent. Keep the fraction while you work—rounded decimals create wrong answers.
Quick reference
| Fraction | Decimal | Percent | Note |
|---|---|---|---|
| 1/3 | 0.3333… | 33.33% | The 3s repeat forever |
| 3/4 | 0.75 | 75% | — |
| 6/7 | 0.8571… | 85.71% | Type 6 ÷ 7 to check |
| 7/8 | 0.875 | 87.5% | — |
How to convert
- Fraction → decimal: divide numerator by denominator (for example, 6 ÷ 7).
- Decimal → percent: multiply by 100 (0.8571… × 100 ≈ 85.71%).
- Percent → decimal: divide by 100 (85.71% → 0.8571).
Round at the end, not the middle
Rounding early adds up. 0.33 × 3 = 0.99, but 1/3 × 3 = 1. And if you round sqrt(2) to 1.4142 and square it, you get 1.99996 instead of 2.
Adding fractions (with steps)
Formula: a/b + c/d = (ad + bc) ÷ bd. Example: 5/6 + 3/8 = 58/48 = 29/24 (that's 1 5/24). The Fraction Calculator shows each step.
Check on the calculator
Type 6 ÷ 7 on the scientific calculator to see about 0.8571. For percent change problems, use the Percent Calculator or read Percent problems: 5 traps to avoid.