Cori has degrees in Elementary Education and Early Childhood Education and has taught lower elementary.
The Different Ways to Multiply
This lesson will cover four different ways to multiply numbers: addition, memorizing the grid method, long multiplication, and drawing lines. Learning about each of them will help you decide which method works best for you.
An error occurred trying to load this video.
Try refreshing the page, or contact customer support.
You must cCreate an account to continue watching
Register to view this lesson
As a member, you'll also get unlimited access to over 84,000 lessons in math, English, science, history, and more. Plus, get practice tests, quizzes, and personalized coaching to help you succeed.
Get unlimited access to over 84,000 lessons.Try it now
Already registered? Log in here for accessBack
- 0:00 The Different Ways to Multiply
- 0:17 The Addition Method
- 0:42 The Grid Method
- 1:37 The Long Multiplication Method
- 2:22 The Drawing Lines Method
- 3:15 Lesson Summary
The Addition Method
One of the most basic ways to multiply is to add. When we multiply two numbers, we're simply adding one number to itself a certain number of times. For example, if the problem says to multiply 20 x 5, you're adding the number 20 to itself five times. So:
20 + 20 + 20 + 20 + 20 = 100
20 x 5 = 100
The Grid Method
When using grid multiplication, you separate your numbers into boxes. The problem in this grid is asking you to multiply 23 x 74. In the top row, the number '23' appears as '20' and '3'. In the first column on the left, the number '74' appears as '70' and '4'.
Multiply the first number in the top row by the first number in the first column:
20 x 70 = 1,400
Then multiply the next number in the top row by 70:
3 x 70 = 210
Next, multiply the first number in the top row by the second number in the first column:
20 x 4 = 80
Finally, multiply 3 x 4 = 12.
Now, add the answers together:
1,400 + 210 + 80 + 12 = 1,702
The Long Multiplication Method
Long multiplication is a way to multiply two multiple-digit numbers. For instance, let's say that a multiplication problem asks you to multiply 364 x 32. Begin by writing the problem on a piece of paper. Then multiply the top number (364) by the bottom right number (2), shown in red, and write that below the line. Now, multiply the top number (364) by the bottom left number (3), shown in blue. When you write your answer down, leave a space for a zero. Then add the two answers together to obtain your final answer:
728 + 10,920 = 11,648
Drawing lines is one of the newer methods of multiplication in the United States. It is a method that has been used by the Japanese. Let's take the problem 12 x 24. To solve the problem, you would first draw lines to represent the numbers given.
These lines are color coordinated with the numbers they represent. The first number in the problem, '1,' and the lines representing it are yellow. The second number, '2,' and the lines representing it are blue. The other numbers, '2' and '4,' are shown in red and green.
After the diagonal lines are drawn, curved lines are drawn to separate the contact points between the lines into sections. Count each contact point in each section, and that will give you the answer to your problem. Section 1 had two contact points (2). Sections 2 and 3 each had eight contact points (8); so the answer to this problem is 288.
There are several ways to solve multiplication problems. Whether you prefer to use addition, since when we multiply we're simply adding one number to itself a certain number of times; long multiplication, or a way to multiply two multiple-digit numbers; grid multiplication, or when you separate your numbers into boxes; or drawing lines, a newer method they use in Japan that involves drawing lines that represent the given numbers, being familiar with each of the different ways can help you decide which method works best for you.
To unlock this lesson you must be a Study.com Member.
Create your account
Register to view this lesson
Unlock Your Education
See for yourself why 30 million people use Study.com
Become a Study.com member and start learning now.Become a Member
Already a member? Log InBack
What Are Different Ways to Multiply?
Related Study Materials
Explore our library of over 84,000 lessons
- College Courses
- High School Courses
- Other Courses
- Create a Goal
- Create custom courses
- Get your questions answered