The minuend is the number being subtracted from.

A subtrahend is a number subtracted from another.

The difference is the result after subtracting one number from another.

When you adjust you make a change to a number. This is done to make a calculation easier to solve mentally.

Explain how adjusting the subtrahend affects the difference: reduction structure

Maths

In this unit pupils will explain how increasing or decreasing the minuend affects the difference and solve subtraction calculations mentally using known facts explaining how adjusting the minuend can make mental calculation easier In the future unit pupils will explain how to balance equations with addition or subtraction expressions and use their knowledge of balancing equations to solve problems

In the prior unit pupils used the concept of same sum to simplify and solve addition problems  In this unit pupils will explain how increasing or decreasing the minuend affects the difference and solve subtraction calculations mentally by using known facts explaining how adjusting the minuend can make mental calculation easier

Use equivalence and compensation to simplify and solve subtraction problems

Which word completes the following sentence?
The more we __________, the less we are left with.

Which word completes the following sentence?
The __________ the subtrahend, the smaller the difference.

Without calculating the value of each expression can you work out which symbol should go between these two expressions?
54 − 23 ___ 54 − 13

Without calculating the value of each expression can you work out which symbol should go between these two expressions?
987 − 156 {{ }} 987 − 256

Without calculating the value of each expression can you work out which symbol should go between these two expressions?
578,234 − 512,293 {{ }} 578,234 − 502,293

Without calculating the value of each expression can you work out which symbol should go between these two expressions?
9.2 − 1.3  {{ }} 9.2 − 1.03

Which value in this bar model is the minuend?

Solve the following calculation mentally by adjusting the minuend and subtrahend.
251− 36 = {{ }}

Solve the following calculation mentally using unitisation.
{{ }} = 620 − 350

Solve the following calculation mentally by adjusting the minuend and then the difference.
1,004 − 800 = {{ }}

Solve the following calculation using a mental strategy.
{{ }} = 202 − 47

Find the missing number in the equation below by adjusting the minuend.
{{ }} = 749,000 − 21,000

This lesson will soon be taken down.

Explain how adjusting the subtrahend affects the difference: reduction structure

Lesson outcome