When you multiply decimals follow these steps:
Multiply the decimals as if they were whole numbers.
For example: 0.02 x 1.2
Multiply without decimals: 2 x 12 = 24
0.02 has two decimal places
1.2 has one decimal place
So the answer has 3 decimal places: 0.02 x 1.2 = 0.024
How does this work?
When you multiply the decimals as if they were whole numbers, you are shifting the decimal point to the right to “get it out of the way”.
We do the simple whole number multiplication:
Now we move the answer back three decimal places (moves):
You place the decimal point in the answer by starting at the right and moving the number of place equal to the sum of the decimal places in both numbers multiplied. In the above example that is 2 decimal places plus 1 decimal place. That’s three decimal places.
Worksheets to practice decimals by decimals
In our grade 4 math section we have a series of worksheets to practice multiplying decimals by decimals.
