Arithmetic Grade Three

Lesson One hundred eighteen: Add and Multiply


Add and Multiply

There are two really easy ways to solve this problem:


      ( 3 + 2 ) x 4
	
METHOD ONE: Add and Multiply - The most obvious thing you can do is add the numbers in the parentheses and then multiply that sum by the number following the multiplication sign.

     ( 3 + 2 ) x 4 =
         5     x 4 = 20

METHOD TWO: Distributive Property - The distributive property says that we can multiply first and then add, like this:

    ( 3 + 2 ) x 4 =
    3 x 4  + 2 x 4 =
     12    +   8  = 20

The fact that there are two ways to solve this problem which both work, is actually kind of neat when you think about it.


Click here to go to next page