Multiplication of a decimal by another decimal is similar to whole number multiplication.
Rules for Multiplication of a Decimal by another Decimal
In the multiplication of a decimal number by another decimal, we first multiply the numbers by ignoring the decimal point.
We count the number of places of decimals in both the numbers and add.
We then put the decimal point before as many places in the product from the right as the number obtained in step above.
In this lesson, we are solving problems that involve multiplication of decimals that have a product less than 0.1
Multiply 0.3 × 0.23
Step 1:
0.3 × 0.23
0.3 has one decimal place and 0.23 has two decimal places, so their product has three decimal places.
Step 2:
So, multiplying 0.3 × 0.23 = 0.069
The product is less than 0.1
Multiply 0.4 × 0.21
Step 1:
0.4 × 0.21
0.4 has one decimal place and 0.21 has two decimal places, so their product has three decimal places.
Step 2:
So, multiplying 0.4 × 0.21 = 0.084
The product is less than 0.1