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Strategies for Multiplication

Strategies for Multiplication. Lacey Unruh, Sara Fisher, and Leslie Jones. Model-Based. Equal Sets. Array. Number Line. 4+4+4+4=16. Model-Based.

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Strategies for Multiplication

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  1. Strategies for Multiplication Lacey Unruh, Sara Fisher, and Leslie Jones

  2. Model-Based Equal Sets Array Number Line 4+4+4+4=16

  3. Model-Based Example Activity: Find as many multiplication expressions for 30 as possible using your blocks, make your expressions into rectangles/squares. Then draw your expression on your paper and write an addition AND multiplication equation to represent your blocks.

  4. Reasoning • Before introducing these strategies make sure students have a strong understanding of the commutative property. • The following reasoning strategies cover 75 of the 100 multiplication facts.

  5. Doubles 3 X 2 = 6 Facts that have 2 as a factor are equivalent to the addition doubles 3 + 3 = 6 Try word problems where 2 is the number of sets, then later switch it up where 2 is the size of sets 5 + 5 = 10 2 X 5 = 10

  6. Fives 5 45 10 Practice skip counting by 5’s at least to 45. http://www.youtube.com/watch?v=GTYxfltyPgg 40 15 20 35 30 25

  7. Zeros and Ones • 36 facts have at least one factor that is either 0 or 1. • Addition problems such as 4 + 0 = 4 can be confused with 4 x 0 = 0. • Ask students to put words with equations • 6 x 0 = 0 in words would be 6 groups of 0 equals 0. • Avoid “rules” such as “any number multiplied by zero is zero.”

  8. Nifty Nines • 3 different patterns for learning 9’s • The tens digit of the product is always one less than the “other” factor and the sum of the two digits in the product is always 9. • Example: 7 x 9, 1 less than 7 is 6, 6 and 3 make 9, so the answer is 63.

  9. Nifty Nines • 7 x 9 is the same as 7 x 10 minus 7. • Students can easily subtract 6 from 60, 5 from 50, 4 from 40, etc…

  10. Nifty Nines • Fingers for finding products of nines • These strategies can be confusing-challenge students to think about why this pattern exists.

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