Lesson 6 Multiplying Whole Numbers 
Multiplication is streamlined version of addition. Suppose you have four cartons of eggs and each carton contains a dozen (12) eggs. How many eggs do you have here?
It is clearly simpler and faster to use the multiplication approach.
Topic 1
Introduction to Multiplying Whole Numbers
Definitions
The multiplication sign (x) indicates the multiplication operation. 
Multiplication problems are sometimes written in a horizontal form such as:
3 x 5 = 15
This form is called a number sentence. It is read as, "Three times five equals fifteen."
There are three different symbols for indicating the multiplication operation in the horizontal form::
Notes

Topic 2
Multiplying With a OneDigit Multiplier
Here is an example of a multiplication problem that has a onedigit multiplier:
52
x 4
First, multiply the 4 times the 2.
Technically speaking this means you should first multiply the multiplier by the 1s digit in the multiplicand52
x 4
8Then multiply the 4 times the 5.
Technically speaking, this means you should then multiply the multiplier by the10s digit in the multiplicand.52
x 4
208The job is done when you have multiplied the multiplier by each of the digits in the multiplicandone at a time, and from right to left.
Important Note from the Author It is likely that you have already mastered the procedures for multiplying whole numbers, and have applied them successfully for a long time. However, this review of multiplication might not be a total waste of your time, because it points out some definitions and underlying principles that need to be more clearly recognized in today's workplaces and learning environments. 
Topic 3
Multiplying With a Multiplier That Has More Than One Digit
When when the multiplier has more than one digit, you need to work with partial products. 
Example
Use these interactive examples and exercises to strengthen your understanding and build your skills:
If would like to see more examples or work on a wider range of exercises, you can go to a more detailed tutorial . 