Commutative, Associative and Distributive Properties 9-1

Commutative, Associative and Distributive Properties for addition and multiplication.
(not for subtraction and division)

a + b   =   b + a
a times b   =   b times a

When you add or multiply two things, you can do them in either order.


(a + b) + c   =   a + (b + c)
(a x b) x c   =   a x (b x c)

When you add or multiply three things, you can start with the first two or the last two.


a times ( b + c )   =   a times b   +   a times c
a x ( b + c )   =   a x b   +   a x c

When you multiply a sum, the multiplication takes place with each of the things in the sum.


Homework for 9-6:  page 20-21;  items 7, 8, 9, 10