Adding and subtracting within one whole

Spine 3: Fractions – Topic 3.4

Primary KS2 Year 3
Mastery PD Materials


Learn to name and write unit fractions. Recognise and show unit fractions of areas, lengths and quantities. Relate numerators and denominators to parts and wholes; explore how the greater the denominators, the smaller the unit fraction.

Teaching points

  • Teaching point 1: When adding fractions with the same denominators, just add the numerators.
  • Teaching point 2: When subtracting fractions with the same denominators, just subtract the numerators.
  • Teaching point 3: Addition and subtraction of fractions are the inverse of each other, just as they are for whole numbers.
  • Teaching point 4: To subtract from one whole, first convert the whole to a fraction where the denominator and numerator are the same.