Multiplication--Part 2 Factors Over Five

Let, me start by saying that I believe that everyone should know their multiplication facts by heart.

In this post, I am going to share a method to help students who do not know their facts to gain confidence.   I am a firm believer, that with continued practice, students will eventually memorize their facts.

For this to work, BOTH numbers need to be larger than 5.  (I do not recommend using 6 x 7 as it is harder to mentally think through when first learning.)

The problem I am using for example is 7 x 8. 
Have students put hands in the air with palms facing them.  Show them the problem written down on a piece of paper.

The conversation should go something like this:

1.  Are both numbers larger than 5?  yes 

2.  This will only work if both numbers are over 5!
3.  Look at the first number which is the 7.  How much over 5 is seven?  2    Bend down 2 fingers on your left hand.

4.  Look at the second factor.  It is a 8.  How much over 8 is 5?  3  Bend down 3 fingers on your right hand.

5. Their hands should look like this.

6.  How many total fingers are bent down?  5                           What is 5 x 10?  50

7.  How many fingers are not bent on your left hand?  3  
8.  How many fingers are not bent on your right hand?  2

9.  What is 3 x 2?  6
10.What is 50 + 6?  56  so 7 x 8 = 56

 

Basic rules:

Both numbers have to be over 5.

Take total number of bent fingers times 10, and then

Multiply the fingers not bent on one hand times the other hand's not bent fingers

Add the two numbers to get the product.

Next time:  Things to make it "fun" to learn multiplication