March 20th and 21st - Investigation 3.1 and 3.2

Investigation 3.1 - Introducing Multiplication of Integers

The goals of today's lesson:

• Use a number line and motion model to develop the relationship between repeated addition and multiplication with integers
• Develop and use algorithms for multiplying integers.

Some of the algorithms uncovered by our students were:

• When two factors have the same sign then the product is positive.
• When two factors have opposite signs the product is a negative number.

Investigation 3.2 

Here is a video showing a different method of understanding the multiplication of integers using a pattern method.