In this worksheet, multiply decimal numbers by whole numbers.

- The
**first stage**is to adjust the question so that there are no decimal numbers. - The
**second stage**is to carry out the multiplication of the whole numbers. - In the
**third stage**, we adjust the answer back to how it should be with decimals.

**Example 1**

Multiply

7.8 × 7

**Answer**

**Stage 1**

Adjust 7.8 so it becomes a whole number.

We do this by multiplying it by 10 to get rid of the decimal place.

7.8 × 10 = 78

This will mean that our answer will now be 10 times too big. But that is fine!

**Stage 2**

Now we work out 78 × 7.

**Stage 3**

Now, remember that this is 10 times too big.

So we divide 546 ÷ 10 = 54.6.

7.8 × 7 = **54.6**

**Example 2**

Multiply

3.68 × 5

**Answer**

**Stage 1**

Adjust 3.68 so it becomes a whole number.

We do this by multiplying it by 100 to get rid of the 2 decimal places.

3.68 × 100 = 368

This will mean that our answer will now be 100 times too big. But that is fine!

**Stage 2**

Now we work out 368 × 5.

**Stage 3**

Now, remember that this is 100 times too big.

So we divide 1840 ÷ 100 = 18.40 = 18.4.

3.68 × 5 = **18.4**