Ctrl+k

Subtract fractions with like denominators

Subtracting fractions with like denominators means finding the difference between quantities partitioned into equal-sized parts: the denominator identifies the unit fraction, so the numerators count the parts being subtracted while the denominator remains unchanged. This includes fractions and mixed numbers with common denominators, including regrouping one whole as equivalent fractional parts when necessary, and interpreting differences with number lines or area models; unlike denominators and more advanced fraction algorithms are not included.

Detailed Explanation: Subtract fractions with like denominators

Fractions with like denominators have the same-sized parts. Keep the denominator the same and subtract the numerators.

For mixed numbers, subtract the whole numbers and the fractional parts. If the top fraction is too small, regroup one whole as fractional parts.

Example

415−2454\frac{1}{5}-2\frac{4}{5}

The denominators are both 55, so the fractions have like denominators.

  1. The fractional part 15\frac{1}{5} is smaller than 45\frac{4}{5}, so regroup one whole from 44.

    Since 11 whole equals 55 fifths,

415=3654\frac{1}{5}=3\frac{6}{5}
  1. Now subtract the fractional parts:

65−45=25\frac{6}{5}-\frac{4}{5}=\frac{2}{5}
  1. Subtract the whole numbers:

3−2=13-2=1
  1. Put the parts together:

415−245=1254\frac{1}{5}-2\frac{4}{5}=1\frac{2}{5}

So, the difference is

125\boxed{1\frac{2}{5}}

The denominator stays 55 because the pieces are still fifths.

Learn by doing: Subtract fractions with like denominators

Click a topic below to practice the foundational skills you'll need, learn the steps, or master this skill

Practice with unlimited practice problems

Fraction Subtraction - Basic (No Simplifying Answers) - No Changed Denominator


    ?