Arithmetic Grade Five

Lesson One hundred and seventy-eight: Distributive Property

Take a close look at the following number sentence: 


	3 * ( 2 + 4 ) = 3 * 2 + 3 * 4
Prove to yourself that it is true by finding the value of the side to the right of the equal sign and the side to the left of the equal sign. 

	LEFT SIDE:   3 * ( 2 + 4) = 3 * 6 = 18

	RIGHT SIDE:  3 * 2 + 3 * 4 = 6 + 12 = 18
This example shows how the distributive property of multiplication works.

Here's another example: 

 
	7 * ( 3 + 2 ) = 7 * 3 + 7 * 2

	LEFT SIDE:   7 * ( 3 + 2 ) = 7 * 5 = 35

	RIGHT SIDE:  7 * 3 + 7 * 2 = 21 + 14 = 35
So, when asked to apply the distributive property you will do something like this: 

	APPLY THE DISTRIBUTIVE PROPERTY.

	  3 * ( 2 + 1 ) =

	ANSWER: 3 * 2 + 3 * 1

      You can change the order like this:
	  2*3+1*3
	You would still be right, but for the 
        next activity don't change the order.
Now you get to try a few of these yourself.

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