Decimal multiplication is like whole number multiplication.
Rules for Multiplication of a Decimal by a Whole Number
In the multiplication of a decimal number by a whole number, we first multiply the numbers by ignoring the decimal point.
We then put the decimal point before as many places in the product as there are in the decimal number.
Multiply 0.13 × 25
0.13 × 25
Multiplying without decimal point 13 × 25 = 325
The number of decimal places in 0.13 is two
The number of decimal places in 25 is zero
So the product has two decimal places, i.e., 3.25
Multiply 0.24 × 18
0.24 × 18
Multiplying without decimal point 24 × 18 = 432
The number of decimal places in 0.24 is two
The number of decimal places in 18 is zero
So the product has two decimal places, i.e., 4.32