Friday, October 16, 2015

Teaching Multiplication for Understanding

One thing I love about the new math standards is teaching for depth of understanding.  It makes so much sense to teach fewer things in depth, than a lot of things with very shallow coverage.  In third grade we spend a great deal of time on multiplication, and students now develop a real understanding of what multiplication is and how it works, rather than just memorizing facts.  Below are some of the strategies that I teach students to use when looking for the product of an unknown fact.

1.  Draw equal groups.  Students model equal groups by drawing a circle of each one, then putting the correct number of objects in each group.

2.  Skip count.  To find the product of 3 X 4, count three fours: 4, 8, 12.  Teach students that these numbers are multiples of 4.

3.  Draw equal jumps on a number line.

4.  Relate multiplication and addition.  3 X 4 = 4 + 4 + 4 + 4

5.  Make an array.

6.  Use the Commutative Property of Multiplication.  If you do not know the product of 3 X 4, perhaps you do know the product of 4 X 3.

7.  Use doubles.  To find the product of 4 X 4, think of the product of 2 X 4 and double it.  To find the product of  6 X 4, think of the product of 3 X 4 and double it, and so on.

8.  Use the Distributive Property of Multiplication to break apart larger factors into smaller factors.
5 X 8 can be thought of as (2 X 8) + (3 X 8).

9.   Make a bar model.

I have developed several items to help my students master both the concept of multiplication as well as multiplication facts.  The products shown below, as well as others, are available in my Teachers Pay Teachers store.