Look at this pizza. It was cut into eight equal slices for a family dinner, and three slices have already been eaten. What fraction of the pizza is left? What fraction is gone? Hands up.

Watch four pizza fractions in turn. For each one, notice the bottom number first — how many equal slices the whole pizza was cut into — then count the shaded slices to read the fraction.

1/2 — one of two parts

3/4 — three of four parts

5/8 — five of eight parts

7/12 — seven of twelve parts

Now we explore the pizza slicer together. Three pupils will take a turn at the board — one each for 1/3, 2/5 and 3/7. The watching class has a job on every fraction:

1. Before the slicer is set, name the bottom number aloud ("three!", "five!", "seven!").
2. Once the slices appear, thumbs up if they look equal in size, thumbs sideways if you'd want one redrawn.
3. After the shading, name the fraction aloud ("one third", "two fifths", "three sevenths").