# Use knowledge of the distributive law to solve two-part subtraction problems

I can use knowledge of the distributive law to solve two part subtraction problems efficiently.

# Use knowledge of the distributive law to solve two-part subtraction problems

I can use knowledge of the distributive law to solve two part subtraction problems efficiently.

## Lesson details

### Key learning points

- Partitioning a factor is called distribution or using the distributive law.
- Partitioned factors can be subtracted to simplify two-part subtraction problems.
- Eight 9s subtract three 9s is equal to five 9s.

### Common misconception

When looking at an expression such as 5 × 6 − 5 × 3 children might be tempted to subtract first leading to an expression like this: 5 × 1 × 3

Ensure that you support the equation with the arrays so that pupils understand where the multiplication expressions come from and they can match the partial products to the arrays.

### Keywords

Common factor - When we compare lists of factors of two or more numbers, any factors that are the same are the common factors.

Distributive law - The distributive law says that multiplying a number by a group of numbers added together is the same as doing each multiplication separately.

### 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).

## Video

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## Starter quiz

### 6 Questions

## Exit quiz

### 6 Questions

4 × 5

3 × 5

6 × 4