 # Using these laws with algebra.  Turn arounds  The "Commutative Law" says that you can swap numbers around and still get the same answer when you add.

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Using these laws with algebra

 Turn arounds  The "Commutative Law" says that you can swap numbers around and still get the same answer when you add or when you multiply  3 + 6 = 6 + 3  5 x 4 = 4 x 5 and =

 The "Associative Law" says that it doesn't matter how you group the numbers when you add or when you multiply. (In other words it doesn't matter which you calculate first.)  (2 + 4) + 5 = 2 + (4 + 5)  5 x (6 x 2) = (5 x 6) x 2

 The "Distributive Law" says you get the same answer when you: * multiply a number by a group of numbers added together * as when you do each multiply separately then add them.  3 x (2 + 4) = (3 x 2) + (3 x 4)  In this example the 3 is distributed across the addition of 2 and 4

 Prove that the commutative law does not apply to subtraction

 Prove that the associative law will not work with division

 Complete these distributive examples –  5 x ( 4 + 7) = (__ x 4) + ( __ x 7) = ___  3 x ( 1 + 6) = ( __ x __) + ( __ x __ ) = ___  (9 x 3 ) + (9 x 2) = __ x ( __ + __ ) = ___

 Jeremy is organising a party. He has invited 9 guests. Each guest will be provided a party hat costing \$1.50 per hat, and a party bag @ \$2 each.  Work out Jeremy’s party costs  Include the distributive law in your workings  Create an algebraic formula that will assist you to work out the party costs for 20 guests

If s=4 and t=5, these statements are true: 3(s+t)=272s+3t=232t-2s=2 Choose values for p and q. Write three true statements using those variables. See if a partner can figure out what your values are.

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