Multiplying and Dividing Decimals

In a Nutshell

Ignore the decimals, do the multiplication, then put the point back in the right place.

To multiply decimals, count the total number of decimal places in both numbers. Multiply as if they were whole numbers, then put the decimal point back so the answer has that many decimal places.

For example, $0.3 \times 0.2$ : one decimal place in each, so two in the answer. $3 \times 2 = 6$ , so the answer is $0.06$ .

To divide by a decimal, multiply both numbers by 10 (or 100) until the divisor is a whole number. Then divide as normal.

1.2 \div 0.4 = 12 \div 4 = 3

First number: Second number:

Use the grid method to break a multiplication into manageable chunks. This is especially helpful when one number has more than one digit.

Watch it work

Question 1: Work out $2.4 \times 1.3$ .

Question 2: Work out $4.56 \div 0.3$ .

Have a go

Q1. Work out $0.6 \times 0.7$ .

Q2. Work out $3.5 \times 4$ .

Q3. Work out $7.2 \div 0.4$ .

Q4. A plank of wood is $2.4$ metres long. It is cut into pieces each $0.16$ metres long. How many pieces are there?