# Use knowledge of column addition and subtraction to calculate with decimal numbers

I can use knowledge of column addition and subtraction to calculate with decimal numbers.

# Use knowledge of column addition and subtraction to calculate with decimal numbers

I can use knowledge of column addition and subtraction to calculate with decimal numbers.

## Slide deck

## Lesson details

### Key learning points

- Numbers are recorded in columns with the same value digits in each column.
- Start with the smallest value column in case numbers need to be regrouped or exchanged.
- If the value of a digit in the minuend is greater than the same digit in the subtrahend, you will need to exchange.
- Make sure that any regrouped numbers are added in with others of the same value.

### Common misconception

Pupils regroup incorrectly, particularly when subtracting e.g. exchanging one ten for ten ones.

Build the calculation using place value counters on a grid set out like a column method. Ask pupils to represent regrouping with counters.

### Keywords

Decimal number - A decimal number has a decimal point followed by digits that show the fractional part.

Regrouping - The process of unitising and exchanging between place values is known as regrouping. For example: ten ones can be regrouped for one ten.

Place value - The value of a digit in a number based on where it is placed.

### Licence

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

## Video

Loading...