Guide · Updated November 2026 · How we check our numbers

Fractions Made Easy: Add, Subtract, Multiply, Divide and Simplify

Fractions follow a few simple rules. Learn them once and every fraction problem becomes routine.

Adding and subtracting

Use a common denominator: a/b + c/d = (ad + bc) ÷ bd. For 3/4 + 2/5: (15 + 8) ÷ 20 = 23/20 = 1 3/20. The least common multiple of the denominators keeps numbers small.

Multiplying

Multiply tops and bottoms: 2/3 × 3/5 = 6/15 = 2/5.

Dividing

Flip the second fraction and multiply: 3/4 ÷ 1/2 = 3/4 × 2/1 = 6/4 = 3/2.

Simplifying

Divide the top and bottom by their greatest common factor (GCF). 18/24 has a GCF of 6, so it simplifies to 3/4.

Decimals to fractions

Write the decimal over a power of 10, then simplify: 0.375 = 375/1000 = 3/8 (dividing by 125).

Mixed numbers

An improper fraction like 11/4 becomes a mixed number by division: 11 ÷ 4 = 2 remainder 3, so 2 3/4.

Try the calculators

➗ Fraction Calculator 🔄 Decimal to Fraction Calculator 🔗 GCF and LCM Calculator

This guide is general information, not professional advice.