Adding and subtracting fractions

Put fractions side by side on bars, then add and subtract them. When the denominators are different, make the parts the same size first.

📖 Start here: read the steps of the “Lesson” in order (1, 2, 3 …) and answer each question. Then continue with “Practice”.

  • UK: Year 3
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Guide

Each bar is one whole. The blue parts are already coloured: that is what you have. The parts you shade turn orange: that is what you add.

When the denominators are the same, all the parts are the same size. So you just count parts: add the numerators and keep the denominator.

When the denominators are different, the parts are different sizes and you can't count them together. Use the + and − buttons to split the bar again until the parts are the same size. This is called finding a common denominator.