Mathematics

Intermediate

50 mins

Teacher/Student led

Learning Goals

Learning Outcomes

Lesson Files

+80 XP

Teacher-led from the board — pupils need no device

What you need:
IWB/Projector/Large Screen

Finding a Fraction of a Quantity

Learn to find a fraction of a quantity by dividing by the denominator to find one part, then multiplying by the numerator. Use ratio bars to model the process and solve real-world shopping problems.

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

Your turn

Your teacher is running this lesson on the board. Here is the part you can try yourself.

Your written work is on page 31

Worked example

1 - Getting Started ~4 mins

Key point

Illustration for Getting Started The bottom number of a fraction tells you how many equal parts to split the amount into, so a smart first step is always to find what one part is worth.

Here is a question to warm us up. Three quarters of the class of 20 walk to school. How many pupils is that? Take a few seconds to think, then hands up if you have a way to start.

👇 Mark your steps as done as you complete them.

+5 XP

2 - Watch and Notice ~11 mins

The bars show four fraction problems worked one at a time. Watch how each whole splits into equal parts, and follow the two steps: divide by the bottom, then multiply by the top. The last one turns it around — we know a part and build back to the whole.

A fraction of an amount

👇 Mark your steps as done as you complete them.

+10 XP

3 - Try It Together ~11 mins

Key point

Each time we split the whole bar into equal parts, find what one part is worth, then take the parts we need.

Today we work through these together on the ratio bars: 3/4 of 24, then 2/5 of 35, then 5/6 of 48.

We'll say each first step out loud before anyone touches the board: how many parts, and what is one part worth?

Work the fractions

+15 XP

4 - Show the Two Steps in Your Copy ~2 mins

COPYBOOK MOMENT

In your maths copy, work each of these problems. For every one, show your two steps clearly: first divide by the bottom to find one part, then multiply by the top to find the answer. Box your answer.

3/4 of 20
2/3 of 18
5/8 of 40

+10 XP

5 - Class Challenge ~8 mins

Here are today's challenges: 3/4 of 24 sweets, then 2/3 of a €30 voucher, then 5/6 of 48 minutes. Each one splits the whole into equal parts, then takes the parts the fraction asks for. We finish with a stretch: working backwards from the parts to find the whole.

Fraction challenge

+15 XP

Pupil practice

Module 3 · Fractions, Decimals and Percentages Number

Lesson 33 · Finding a Fraction of a Quantity

Download Activity Book page (PDF)

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