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

An unknown is a quantity that has a set value but it is represented by a symbol or letter.

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

A part is a piece or section of the whole.

Solve calculations with missing parts

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

A quantity that has a set value represented by a symbol or letter

An answer you give when you don’t know the answer

Which of the following best describes an unknown?

What is the mass of the plasticine on the balance scale?

Without using a written method, calculate the unknown value in the pair of equations shown.

Without using a written method, calculate the unknown.

Tick the two numbers that are complements to 1,000

Tick the two numbers that are decimal complements to 10

What is the missing number in this equation?
{{ }} + 61 = 150

What is the missing number in this equation?
26 + {{ }} + 11 = 70

What is the missing number in this equation?
{{ }} + 45 + 18 = 89 + 6

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

Solve calculations with missing parts

Lesson outcome

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