Multiplication Facts Using Strategies

David McKillop

Making Math Matter, Inc.

Why should students learn the number facts?

They are the basis of all mental math strategies, and mental math is the most widely used form of computation in everyday life

Knowing facts is empowering Facilitates the development of other

math concepts

How is fact learning different from when I learned facts?

1. Facts are clustered in groups that can be retrieved by the same strategy.

2. Students can remember 6 to 8 strategies rather than 100 discrete facts.

3. Students achieve mastery of a group of facts employing one strategy before moving on to another group.

General ApproachFor each cluster of facts that you are going to introduce, start by showing students one of the facts and ask them to put up their hands when they have the answer. Then ask some student(s) to explain how they did it. This can lead to a discussion of a variety of strategies from which you can extract the one you will highlight. Students should understand that they can use whatever strategy makes sense to them and enables them to get an answer in a reasonable time frame. You will be highlighting a specific strategy for each cluster but students may use other ones. Therefore, during the reinforcement activities when you ask students to explain their strategy, you should be open to, and welcome, any strategy that is reasonable. You don’t want to lose sight of the mission to have students be flexible in their thinking. As well, you will have students who know facts automatically without using a strategy, so you should be open to “I just knew it.” when you ask to explain how they did it. In fact, our long-term goal would be automaticity of the facts for all students.

General Approach Introduce a strategy using association,

patterning, contexts, concrete materials, pictures – whatever it takes so students understand the logic of the strategy

Practice the facts that relate to this strategy, reducing wait time until a time of 3 seconds, or less, is achieved. Constantly discuss answers and strategies.

Integrate these facts with others learned by other strategies.

IT WILL TAKE TIME!

Facts with 2s:2 x ? and ? X 2

Highlighted Strategy: Connect to Doubles in Addition

Start with 2 x ?

Relate ? X 2 to 2 x ?

Practice the Facts Webs Dice games Card games Flash cards

Facts with 9s:? X 9 and 9 x ?

Highlighted Strategy: Nifty Nines Strategy: Two Patterns -Decade of answer is one less than the number of 9s and the two digits of the answer sum to 9

9 x 9 = 81 8 x 9 = 72 7 x 9 = 63 6 x 9 = 54 5 x 9 = 45 4 x 9 = 36 3 x 9 = 27

Practice the Facts Calculator

Facts with 5s The Clock

Strategy: The number of 5s is like the minute hand on the clock – it points to the answer. For example, for 4 x 5, the minute hand on 4 means 20 minutes; therefore, 4 x 5 = 20.

Practice Strategy Selection

Which facts can use The Clock Strategy?

Which facts can use the Nifty Nines Strategy?

Which facts can use the Doubles Strategy?

3 x 5 5 x 9 8 x 2 9 x 7 9 x 2 2 x 5 7 x 5 6 x 9

Facts with 0s Highlighted

Strategy: The Tricky Zeros: All facts with a zero factor have a zero product.

(Often confused with addition facts with 0s)

If you have 6 plates with 0 cookies on each plate, how many cookies do you have?

Facts with 1s Highlighted

Strategy: The No Change Facts: Facts with 1 as a factor have a product equal to the other factor.

If you have 3 plates with 1 cookie on each plate OR 1 plate with 3 cookies on it, you have 3 cookies.

Facts with 3s Highlighted

Strategy: The Double and One More Set Strategy. For example, for 3 x 6, think: 2 x 6 is 12 plus one more 6 is 18.

Facts with 4s Highlighted

Strategy: The Double-Double Strategy.

For example, for 4 x 6, think: double 6 is 12 and double 12 is 24.

The Last Nine Facts

6 x 6 6 x 7 and 7 x 6 6 x 8 and 8 x 6 7 x 7 7 x 8 and 8 x 7 8 x 8

Have students suggest strategies for these.

Possible Strategy: Using helping facts:

6 x 6 = 5 x 6 + 6

7 x 6 = 5 x 6 + 2 x 6

6 x 8 = 5 x 8 + 8

7 x 8 = 5 x 8 + 2 x 8

8 x 8 = 4 x 8 x 2

• Some know 8 x 8 is 64 because of a chess board

• What about 7 x 7?

Practice the Facts Flash cards Bingo Dice Games Card Games Fact Bee Calculators