Lesson 5 Multiplying Decimals 
The procedures for multiplying decimal fractions is almost the same as multiplying whole numbers. The only difference is that we have to deal with the decimal points in the decimalfraction versions—but not until the final step.
Procedure Multiplying Decimals Step 1: Write the decimal values in vertical form, aligning the righthand digits in the factors.
Step 2: Perform the multiplication operation without paying any attention to the decimal points.
Step 3: Count the total number of digits to the right of the decimal points in the factors. Count that many places to the left in the product, and place the decimal point there.

There is no need to waste your time here working through cumbersome multiplication problems. You have already mastered the procedure. The new thing here is placing the decimal point in the solution: The number of decimal places in the answer is equal to the sum of the number of decimal places in the multiplication factors.
Exercises
Multiplying Decimals
If you are having any trouble understanding the content of this lesson, you will benefit from a more detailed tutorial on the subject. 