The Commutative Property of Multiplication

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The Commutative Property of Multiplication

• Created by Miss Henry

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What Is It??

• The Commutative Property says that For all real
  numbers a and b, a b b
  a
• This means we can multiply numbers in any order
  we want without changing the final answer!

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Where Did It Come From??

• The word commutative was first used by François
  Joseph Servois in a memoir published in Annales
  de Gergonne in 1814
• He was born on July 19, 1768, in Mont-de-Laval,
  Doubs, France and died on April 17, 1847, in
  Mont-de-Laval, Doubs, France
• This means he was almost 79 years old!!

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Why Is It Helpful??

• The word COMMUTATIVE comes from the word commute,
  which means to move around
• This property allows us to move the numbers
  around to make multiplying much easier!

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What Are Some Examples?

• The following equations show the Commutative
  Property
• 1. Does 8 5 5 8 ??
• Answer YES! (Both are equal to 40!)
• 2. Does 12 10 10 12 ??
• Answer YES! (Both are equal to 120!)

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Can You Use It?

• How can you use the Commutative Property to make
  simplifying easier?
• 1. 7 5 9 2
• Answer Commute the 5 and 2 and do mental math!
• 7 5 9 2
• 7 9 5 2
• 63 10
• 630

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Can You Use It Again?

• How can you use the Commutative Property to make
  simplifying easier?
• 1. 4 x 9 x
• Answer Commute the x and 9 and combine like
  terms!
• 4 x 9 x
• 4 9 x x
• 36 x x
• 36x2

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The End!!!
This lesson was created by Mary Brown Joe
Smith Sarah Green