Arithmetic Grade Six

Lesson Fifty-eight: Multiplying Signed Numbers

Multiplying signed numbers is just like multiplying unsigned numbers except that you have to keep track of the sign. Here are some examples: 

	-5 x 6 = -30			-5 x -6 = 30

	5 x -6 = -30			 5 x 6  = 30
As you can see each of the products shown above come out to 30 or -30. So, how do you know which are negative and which are positive. The rules are simple: 

	positive x positive = positive
	positive x negative = negative
	negative x positive = negative
	negative x negative = positive
That last rule might surprise you since you might not expect a negative multiplied by a negative to be positive, but that's the rule!

You get to try a few for yourself on the next page.

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