An equation is used to show that one number, calculation or expression is equal to another.

An adjustment is a change to a number using either subtraction or addition. This can be done to a part or a whole.

The whole is all the parts or everything, the total amount.

Explain how adjusting one part affects the sum

Maths

In this unit pupils used the concept of same sum to simplify and solve addition problems. In the future unit pupils will solve calculations with missing addends and use the same difference rule to balance equations. They will explain how increasing or decreasing the minuend affects the difference.

In the prior unit pupils identified structures within stories using their knowledge of structures to create stories. They used their knowledge of additive structures to solve problems. In this unit pupils used the concept of same sum to simplify and solve addition problems

Use equivalence and compensation to simplify and solve addition calculations

The inverse process is used to undo the adjustment.

In an addition equation, if one part is adjusted and the other parts remain the same, what happens to the whole?

If a part is adjusted by adding 400 and the other parts remain the same, what will need to be done to the whole?

If a part is adjusted by subtracting 4.06, what will need to be done to the whole?

Aisha has 36 Battle Robot Cards and Sofia has 56, so between them they have a collection of 92 cards.
Aisha is given 15 more for her birthday. How many do they have between them now?

The diagram shows Aisha and Sofia’s joint score in a paired arcade game. At the end of the game, Aisha gets a penalty reduction in points of 1,350. What is their joint total now?

Aisha and Sofia’s pet cats have a combined weight of 15.4kg. After a month, Sofia’s cat loses 0.7kg in mass. Their new combined mass = {{}} kg

What is the missing number in this part-whole model?

In digits, write the number being represented by the place value counters.

What is the unknown in this equation?   4.3 + {{ }} = 4.1 + 1.5

This lesson will be removed by end of Summer Term 2025.

Explain how adjusting one part affects the sum

Lesson outcome

This lesson will be removed by end of Summer Term 2025.