Multiplying decimals is just like multiplying whole numbers, but with an extra step at the end. Here's how you can do it:
Line up the decimal points: Put the decimal point in each number directly under the other one.
Multiply the numbers just like you would with whole numbers: Ignore the decimal points and multiply the numbers as you normally would.
Put the decimal point in the answer: Count the total number of decimal places in the numbers you are multiplying (the spaces to the right of the decimal point). Then, put the decimal point in the answer directly over that many spaces from the right.
For example, to multiply 0.6 x 0.3, we line up the decimal points and multiply:
0.6 x 0.3 0.18
The answer is 0.18. We have a total of two decimal places, so we put the decimal point in the answer directly over two spaces from the right.