Here is a pizza cut into eight equal slices, but three of them have already been eaten. Hands up: what fraction of the pizza is gone, and what fraction is still on the plate?

Here are four pizzas, each already cut into a different number of equal parts. Look at how many equal parts there are and how many are shaded. Notice what happens to the size of each slice as the number of parts grows.

Now we try it together. I will call out a fraction, and one pupil will come to the board to slice the pizza into the right number of equal parts and shade the right number of them. While they work, the rest of us read the fraction back out loud together to check it is right.

Now we fold and shade real fractions. Take a paper strip and fold it into halves, then quarters, then eighths. Each time you fold, shade and label the fraction your teacher calls. The fold lines show you the equal parts.

We have a new pair of words for the top and bottom numbers. Take the pizza we already know: 5/8. Eight equal parts, five shaded.

• The bottom number is 8. Its special name is the denominator. It tells how many equal parts the whole is split into.
• The top number is 5. Its special name is the numerator. It counts how many of those parts are shaded.

Name it out loud together: numerator 5, denominator 8, five-eighths.

What we learned today

• A fraction names how many of the equal parts of a whole we have.
• The denominator (bottom number) sets how many equal parts there are, so it sets the size of each part.
• The numerator (top number) counts how many of those parts we have shaded.
• The same whole cut into more parts gives smaller parts.
• We name a shaded fraction by saying the numerator and the denominator.