Wednesday, August 28, 2013

Commutative and associative properties

As you have seen in our math classes, we've been studying the properties of numbers. So, let's take a look at them:

  • The Commutative Property of Addition and Multiplication
3 + 2 = 2 + 3
(5 = 5)
3 x 6 = 6 x 3
(18 = 18)
If you change the order of the numbers, the results won't change.

Remember: You can only use the Commutative Property with Addition or Multiplication. Don't use it with Subtraction or Division.


  • The Associative Property of Addition and Multiplication
(2 + 3) + 7 = 2 + (3 + 7)
(5) + 7 = 2 + (10)
12 = 12

(2 x 3) x 4 = 2 x (3 x 4)
(6) x 4 = 2 x (12)
24 = 24

Moving the parentheses will not affect the results.


Let's Practice

Use the commutative property to solve the equations:

a) 2 x 3 x 2 = 2 x 2 x 3
b) 3 + 4 + 12 = 3 + 12 + 4
c) 32 x 2 = 2 x 32
d) 44 + 3 + 15 = 44 + 15 + 3
 
 
Now use the associative property to solve:
a) (123 + 3) + 23 = 123 + (3 + 23)
b) (9 x 8) x 2 = 9 x (8 x 2)

2 comments:

  1. a) 12
    b) 19
    c) 64
    d) 62

    2)a) 149
    b) 144
    leonardo

    ReplyDelete
  2. a)12- 12
    b) 19- 19
    c) 64- 64
    d) 62-62

    a)149-149
    b)144-144

    BY HEDRA MARQUES

    ReplyDelete