Mathematics

Intermediate

50 mins

Teacher/Student led

Learning Goals

Learning Outcomes

Lesson Files

+80 XP

Teacher-led from the board. Pupils do not need a device, but can follow on one.

What you need:
IWB/Projector/Large Screen

The Equals Sign Means Balance

Explore what the equals sign really means by using scales to show that both sides of a number sentence must weigh the same. Build matching sums and recognise true and false number sentences.

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1 Getting Started
2 Watch and Notice
3 Try It Together
4 Write True Sentences 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 111

Balance scales

1 - Getting Started ~4 mins

Illustration for Getting Started A number sentence is a maths statement with numbers and an equals sign, like 5 + 2 = 7. Look at this claim on the board: 5 + 2 = 7, and then 7 = 5 + 2. Is the second one allowed? Hands up: does the equals sign only work with the answer on the right, or can the answer sit on the left too?

👇 Mark your steps as done as you complete them.

+5 XP

2 - Watch and Notice ~9 mins

Watch three sets of scales. Look at whether the beam is level or tilted, and read what is on each pan. When is the beam level, and what does a level beam tell us?

Check: what does the beam tell us?

The left pan makes 7 and the right pan is 7. The beam is level, so the two sides match and 5 + 2 = 7 is true.

Hands up: is that beam telling us the two sides match, or not?

Check: what does the beam tell us?

The left pan makes 7, but the right pan is 8. The beam tips down on the heavier side, so the two sides do not match and 4 + 3 = 8 is not true.

This last one is the surprise. One pupil predicts: can two different-looking sides still balance?

Check: what does the beam tell us?

Both sides look different, but each one makes 10. The beam is level, so 6 + 4 = 3 + 7 is true.

👇 Mark your steps as done as you complete them.

+10 XP

3 - Try It Together ~11 mins

Now it is your turn on the board. One pan shows 7 and the other pan is empty. Build a sum on the empty pan so the beam sits level. There is more than one right answer, so find a few different sums that all make 7.

Level the scales

+15 XP

4 - Write True Sentences in Your Copy ~3 mins

COPYBOOK MOMENT

In your maths copy, write three true number sentences that balance. Use a different total for each one, for example:

3 + 4 = 7
6 + 2 = 8
5 + 4 = 9

Then write one number sentence that does not balance. Tick the three true ones.

+10 XP

Pupil practice

Module 10 · Algebra: Patterns, Rules and Number Sentences Algebra

Lesson 120 · The Equals Sign Means Balance

Download Activity Book page (PDF)

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The Equals Sign Means Balance

Teacher Class Feed

1 - Getting Started ~4 mins

2 - Watch and Notice ~9 mins

3 - Try It Together ~11 mins

Level the scales

4 - Write True Sentences in Your Copy ~3 mins

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