Video:How to Multiply by 1

Transcript:How to Multiply by 1

Hi, I'm Jen D'Amore for About.com, and this video is all about how to multiply by 1. 1 is a whole number.

Finding 1 on the Multiplication Table

Let's start first by studying the multiplication table. Find the 1 on one side, and the number you'd like to multiply on the other side, follow that row and column until they meet to find your answer.  

So, 1 x 1 = 1, 1 x 2 = 2, 1 x 3 = 3 and so on.

As you can see, any number multiplied by one is equal to itself. This is a mathematical rule known as the "identity property of multiplication," or the "multiplication property of one." 1 is an empty product, since it does not change the number it is multiplying. 

Using 1 in Algebra and Word Problems

If you're solving an algebraic equation, and it, or part of it is being multiplied by one, you can simplify the equation. For example:  1(a +b) = a+b.

You can also simplify word problems, by identifying where multiplication by "1" simplifies. If a word problem refers to "A batch, a group, or other cluster" in the singular, that batch can be assigned the numerical integer 1, and if being multiplied in the problem, it will simplify it for you and make it easier to solve.   

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