Children investigate equivalent fractions through calculation – by multiplying or dividing the numerator and denominator by the same number, identifying that they have multiplied or divided by 1.
Children investigate fractions in their simplest form (lowest possible numerator) –  by dividing the numerator and denominator by their highest common factor, identifying that they have divided by 1.
They use their understanding of equivalent fractions using concrete material and the relationship between the numerator and denominator, and highest common factors. Children who have not yet demonstrated understanding of these concepts, will investigated these Levels – Fractions and Decimals 13, Multiplication and Division 20.