Subtract from a 2-digit number using column subtraction with regrouping

I can subtract from a 2-digit number using column subtraction with regrouping.

Download all resources

Share activities with pupils

New

Year 3

Subtract from a 2-digit number using column subtraction with regrouping

I can subtract from a 2-digit number using column subtraction with regrouping.

Download all resources

Share activities with pupils

Slide deck

Download slide deck

Skip slide deck

Lesson details

Key learning points

Start with the numbers with the smallest place value.
Regroup when the ones digit of the subtrahend is greater than the ones digit of the minuend.
Change the number of ones and tens in the minuend.

Common misconception

Pupils may not understand column subtraction. They may use regrouping without grasping the reasoning behind the algorithm.

Ensure that pupils understand the purpose of regrouping and the value of the numbers when they are using column subtraction. Spend more time using base ten blocks with regrouping if pupils are not ready to progress onto the formal algorithm.

Keywords

Column subtraction - Column subtraction is a way of subtracting numbers by writing a number below another.
Regroup - The process of unitising and exchanging between place values is known as regrouping.

In this lesson, pupils use column subtraction to regroup for calculations where the ones number of the subtrahend is greater than the ones number of the minuend. Take time using base 10 blocks to show this process alongside the written method to support understanding.

Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).