Preparing for fractions: the part–whole relationship

Spine 3: Fractions – Topic 3.1

Primary KS2 Year 3
Mastery PD Materials


Identify parts and wholes of areas, lengths and sets. Identify equal and unequal parts; make judgements about the relative size of a part to a whole. Find the whole when the size of a part and number of equal parts is known.

Teaching points

  • Teaching point 1: Any element of a whole is a part; if a whole is defined, then a part of this whole can be defined.
  • Teaching point 2: A whole can be divided into equal parts or unequal parts.
  • Teaching point 3: The relative size of parts can be compared.
  • Teaching point 4: If one of the equal parts and the number of equal parts are known, these can be used to construct the whole.