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Fraction Calculator

Adding, subtracting, multiplying or dividing fractions requires a common denominator or cross-multiplication. Enter both fractions and pick an operation for an instant, simplified answer.

結果

5/6

Result

As a decimal
0.8333
How this was calculated
  1. 1Operation1/2 + 1/3 = 5/6
  2. 2Simplifiedggd(5, 6) = 5/6

公式

Add/subtract: (a×d ± c×b) / (b×d) — Multiply: (a×c) / (b×d) — Divide: (a×d) / (b×c)

For addition and subtraction you first find a common denominator (b×d) and adjust the numerators accordingly. For multiplication you multiply numerator by numerator and denominator by denominator. For division you multiply by the reciprocal. The result is then simplified by dividing by the greatest common divisor (GCD) of the numerator and denominator.

計算例

1/2 + 1/3

→ (1×3 + 1×2) / (2×3) = 5/6.

3/4 − 1/4

→ 2/4, simplified to 1/2.

2/3 × 3/4

→ 6/12, simplified to 1/2.

よくある間違い

  • When adding or subtracting, adding the numerators directly without first finding a common denominator.
  • When dividing, forgetting to flip (take the reciprocal of) the second fraction before multiplying.

活用シーン

  • Adjusting recipes that use fractional measurements, like 3/4 cup.
  • Checking homework involving fractions.
  • Adding measurements for DIY projects, like board thicknesses in inches.

よくある質問

Why is my result automatically simplified?

A simplified fraction (like 1/2 instead of 2/4) is the standard form and easier to read and compare.

Can I enter negative fractions?

Yes, enter a negative number in the numerator or denominator; the sign is handled correctly in the result automatically.

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