Decimal multiplication is done in a similar way as whole number multiplication.
Rules for Decimal Multiplication
First we multiply the decimal numbers as if they were whole numbers by ignoring the decimal points.
Here the decimal points are not lined up vertically as in addition and subtraction. Here the digits are lined up to the right.
The number of digits after the decimal point in both the numbers are counted and added.
In the final product, a decimal point is placed before that many digits from the right.
Multiply 13.4 × 0.35
Step 1:
13.4 × 0.35
We line up the digits and not the decimal points
We now multiply the numbers by ignoring the decimal points and assuming as if they were whole numbers.
Step 2:
13.4 has one decimal place. 0.35 has two decimal places. So the product of these numbers has three decimal places.
Multiply 16.5 × 0.27
Step 1:
16.5 × 0.27
We line up the digits and not the decimal points
We now multiply the numbers by ignoring the decimal points and assuming as if they were whole numbers.
Step 2:
16.5 has one decimal place. 0.27 has two decimal places. So the product of these numbers has three decimal places.