Multiplying a decimal by an integer
Multiplying a decimal by an integer (whole number) is pretty straightforward to do, as long as you understand how to multiply and divide by 10 or 100 and you know your times tables.
The only difference between the calculation 0.3 x 6 and 3 x 6 is the place value of the 3. 0.3 is 10 times smaller than 3 (3 ÷ 10 is 0.3). So the answer to 0.3 x 6 will be 10 times smaller than the answer to 3 x 6.
3 x 6 = 18, so 0.3 x 6 = 1.8.
This also applies to calculations such as 0.03 x 24. Here, 0.03 is 100 times smaller than 3, so the answer is also 100 times smaller.
3 x 24 = 72, so 0.03 x 24 = 0.72.
- BBC Bitesize: Notes and a couple of problems to try.
- IXL: Online questions with solutions.
- Manga High: Online game/question with solutions.
- Maths is Fun: Multiplying decimals animation.
- Mymaths: Interactive lesson on multiplying decimals by whole numbers. Test yourself with the online homework.
- Virtual Nerd: Video tutorial with worked examples.