Mathematics

Intermediate

50 mins

Teacher/Student led

Learning Goals

Learning Outcomes

Lesson Files

+80 XP

What you need:
IWB/Projector/Large Screen

Adding and Subtracting Fractions with the Same Bottom Number

Learn to add and subtract fractions that share the same bottom number by combining the numerators, and discover what happens when your slices fill exactly one whole pizza.

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1 Getting Started
2 Watch and Notice
3 Try It Together
4 Work It in Your Copy
5 Class Challenge
6 What Did We Notice?
7 What's Next
Pupil practice

1 - Getting Started ~4 mins

Here is a pizza cut into eight equal slices. Two slices are already on your plate, and you reach for three more. Someone worked it out as 2/8 + 3/8 = 5/16 — the tops added AND the bottoms added.

Key point

Have a good look. Is the answer 5/16, or something else? What would you tell them?

👇 Mark your steps as done as you complete them.

+5 XP

2 - Watch and Notice ~9 mins

The interactive shows four pizzas with like fractions already shaded. Look at the shaded slices on each one, and count them with me.

👇 Mark your steps as done as you complete them.

+10 XP

3 - Try It Together ~10 mins

Key point

Today we work through these on the pizza together: 3/8 + 2/8, then 6/8 − 1/8, and finally 4/8 + 4/8. Say each answer aloud before we shade it. The last one fills the whole pizza, so watch what the shaded slices tell us.

Slice and total like fractions

+15 XP

4 - Work It in Your Copy ~3 mins

COPYBOOK MOMENT

Before you open your copy, watch one worked example on the board so you can see the written layout.

We will write 2/8 + 3/8 with the two fractions one above the other, like this:

2/8
+ 3/8
= 5/8

Add the top numbers only (2 + 3 = 5). The bottom number stays 8 because the slices stay eighths. That is the full method.

Now in your maths copy, work each sum or difference the same way: write the two fractions one above the other and combine the numerators. Remember: the bottom number stays the same. If your answer fills exactly one whole, circle it. You do not need to name it any other way today.

3/8 + 2/8
7/10 − 4/10
4/6 + 2/6

+10 XP

5 - Class Challenge ~7 mins

Today the pizza gives you a target fraction to make each time. Work through them in order: 5/8, then 3/8, then 6/6, then 5/6, then 7/10. Watch for the one that fills every slice on the pizza.

Make the target fraction

+15 XP

Pupil practice

Module 3 · Fractions, Decimals and Percentages Number

Lesson 38 · Adding and Subtracting Fractions with the Same Bottom Number

Download Activity Book page (PDF)

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