How to use
- Enter the first fraction, for example 1 1/2, choose add, subtract, multiply or divide, and enter the second fraction.
- Read the answer as a fraction, mixed number, exact decimal and percent.
- Follow the numbered steps underneath to see how the answer was reached, or switch to Expression or Simplify.
Options explained
- Input format
- Write fractions as 3/4, mixed numbers with a space as 1 1/2; decimals are converted, so 0.25 becomes 1/4.
- Simplifying
- Results are reduced by the greatest common divisor, with a positive denominator.
- Expression
- Type a whole calculation such as 1/2 + 3/4 × (2 − 1 1/3). Multiplication and division are done before addition and subtraction, brackets first.
- Repeating decimals
- Put the repeating part in brackets — 0.(3) is 1/3 and 0.1(6) is 1/6. Results show the exact decimal the same way, so 1/7 = 0.(142857).
Examples
| Sum | Result | Mixed number | Decimal |
|---|---|---|---|
| 1/2 + 1/3 | 5/6 | 5/6 | 0.833333 |
| 1 1/2 + 3/4 | 9/4 | 2 1/4 | 2.25 |
| 2/3 × 9/4 | 3/2 | 1 1/2 | 1.5 |
| 1/2 ÷ 1/4 | 2 | 2 | 2 |
Worked examples
| Problem | Answer | Mixed number | Decimal |
|---|---|---|---|
| 1/2 + 1/3 | 5/6 | — | 0.8333… |
| 3/4 − 1/6 | 7/12 | — | 0.5833… |
| 7/8 − 1/4 | 5/8 | — | 0.625 |
| 2/3 × 3/8 | 1/4 | — | 0.25 |
| 5/6 ÷ 2/3 | 5/4 | 1 1/4 | 1.25 |
| 1 1/2 + 2 3/4 | 17/4 | 4 1/4 | 4.25 |
How each operation works
Adding and subtracting. Rewrite both fractions over a common denominator, then add or subtract the tops: 1/2 + 1/3 = 3/6 + 2/6 = 5/6.
Multiplying. Multiply the tops and the bottoms, then simplify: 2/3 × 3/8 = 6/24 = 1/4.
Dividing. Flip the second fraction and multiply: 5/6 ÷ 2/3 = 5/6 × 3/2 = 15/12 = 5/4.
Mixed numbers. Type them with a space, such as 1 1/2. They are turned into improper fractions first (1 1/2 = 3/2), so 1 1/2 + 2 3/4 = 3/2 + 11/4 = 17/4 = 4 1/4.
Frequently asked questions
How do you divide fractions?
Multiply by the reciprocal — 1/2 ÷ 1/4 = 1/2 × 4/1 = 2.
Is it exact for large numbers?
Yes. It uses exact integer arithmetic, so there is no rounding error.
Can I work with more than two fractions?
Yes. Switch to Expression and type the whole calculation, for example 1/2 + 1/3 + 1/6, with brackets where needed.
How do I turn a decimal into a fraction?
Switch to Simplify and type the decimal. 0.375 becomes 375/1000 = 3/8; for a repeating decimal write the repeating digits in brackets, such as 0.(6) for 2/3.
Privacy
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