##### Related Pages

# Inverse Operations

(KS2, Year 4)

## The Lesson

An inverse operation is the opposite of an operation. It reverses an operation.If the inverse operation reverses the operation, the operation reverses the inverse operation.

## Addition and Subtraction

The inverse operation of addition is subtraction.Imagine we

**add**2 to 3...

3

...we can reverse the operation by **+ 2**→ 5**subtracting**2:

3 ← 5

Subtraction has reversed the addition. **− 2***Subtraction is the inverse operation of addition...*

## ...and Vice Versa

If subtraction is the inverse operation of addition, the inverse operation of subtraction is addition. Imagine we**subtract**2 from 3...

3

...we can reverse the operation by **− 2**→ 1**adding**2:

3 ← 1

Addition has reversed the subtraction. **+ 2***Addition is the inverse operation of subtraction.*

## Multiplication and Division

The inverse operation of multiplication is division.Imagine we

**multiply**4 by 2...

4

...we can reverse the operation by **× 2**→ 8**dividing**by 2:

4 ← 8

Division has reversed the multiplication. **÷ 2***Division is the inverse operation of multiplication...*

## ...and Vice Versa

If division is the inverse operation of multiplication, the inverse operation of division is multiplication. Imagine we**divide**4 by 2...

4

...we can reverse the operation by **÷ 2**→ 2**multiplying**by 2:

4 ← 4

Multiplication has reversed the division. **× 2***Multiplication is the inverse operation of division.*

## Squaring and the Square Root

The inverse operation of squaring is taking the square root.Imagine we

**square**3...

3

...we can reverse the operation by taking the **→ 9**^{2}**square root**:

3 ←

The square root has reversed the squaring. **√9***The square root is the inverse operation of squaring...*

## ...and Vice Versa

If the square root is the inverse operation of squaring, the inverse operation of the square root is squaring. Imagine we take the**square root**of 4...

**√**4 → 2

**squaring**:

4 ← 2

Squaring has reversed the square root. ^{2}*Squaring is the inverse operation of the square root.*

## Why Is an Inverse Operation Useful?

## Checking Your Answer

The inverse operation is useful for checking your answers. Imagine you multiply 6 by 4:
6 × 4 = 24

The inverse operation of multiplication is division. Divide your answer by 4 to see if you get back to 6:
24 ÷ 4 = 6 ✔

## Top Tip

## Inverse Operations

The inverse operations are summarised below:**Help Us To Improve Mathematics Monster**

- Do you disagree with something on this page?
- Did you spot a typo?