Fractions, Decimals & Percents
Converting and computing with fractions, decimals and percentages
Explanation
Conversions
| Fraction | Decimal | Percent |
|---|---|---|
| 1/2 | 0.5 | 50% |
| 1/4 | 0.25 | 25% |
| 3/4 | 0.75 | 75% |
| 1/5 | 0.2 | 20% |
| 1/3 | 0.333… | 33.3% |
| 2/3 | 0.666… | 66.7% |
Fraction → Decimal: divide numerator by denominator.
Decimal → Percent: multiply by 100.
Operations with Fractions
- Add/Subtract: common denominator required. 2/3 + 1/4 = 8/12 + 3/12 = 11/12
- Multiply: straight across. 2/3 × 3/5 = 6/15 = 2/5
- Divide: keep-change-flip. 2/3 ÷ 4/5 = 2/3 × 5/4 = 10/12 = 5/6
- Mixed numbers: convert to improper fractions first. 1½ = 3/2
Percent Problems
Use: Percent × Whole = Part (convert percent to decimal first)
- 30% of 80 = 0.30 × 80 = 24
- What % of 50 is 20? → 20/50 = 0.4 = 40%
- 15 is 25% of what? → 15 ÷ 0.25 = 60
Practice Questions
Test your knowledge of Fractions, Decimals & Percents with a timed quiz.
Take Quiz →Topics in Mathematics Achievement