Tic-Tac-Toe and Integer Multiplication & Division

By | September 8, 2016

Is the result supposed to be positive or negative ?

The answer to this question is as easy as determining the winner of a game of Tic-Tac-Toe.

First, draw the famous Tic-Tac-Toe board which is just a pound sign or hashtag, #.

Screen Shot 2016-08-31 at 10.10.06 PM

Second, place positive signs down the diagonal.

Screen Shot 2016-08-31 at 10.05.53 PM

Next place negative signs in the remaining open spaces.

Screen Shot 2016-08-31 at 10.14.51 PM

Now just follow the signs diagonally, horizontally or vertically as you would in a winning Tic-Tac-Toe game.

Screen Shot 2016-08-31 at 11.18.56 PM

Row 1

left to right ===> positive times a negative results in a negative.

right to left ===> negative times a negative results in a positive.


Row 2

left to right ===> negative times a positive results in negative.

right to left ===> negative times a positive results in negative.


Row 3

left to right ===> negative times a negative results in a positive.

right to left ===> positive times a negative results in a negative.


Diagonals

top left to bottom right ===> positive times a positive results in a positive.

top right to bottom left ===> negative times a positive results in a negative.


Top to bottom and Bottom to Top

You follow the same rules when going from top to bottom or from bottom to top.

 

This method works for both Multiplication & Division of integers.

I hope that this helps!

Shout out to the math staff at Azalea Gardens Middle School.  They shared this teaching tool with me and now I am sharing it with you!