1. x = x = x = x = x = x = x = x = x = x = x = x = 4 Story Problems (variables can be any letter) 1.z + 3 = 184. p = 12 years 2.z = 15 years – t = 14.2; t = 1.6 hours 3.p – 8 = (-1) + s = -8; s = -2 par

Commutative means that the order does not make any difference. a + b = b + aa b = b a Examples = = 3 2 The commutative property does not work for subtraction or division.

Using the Commutative Property = –54 + (–16) + 35 = – = –35 Change subtraction to addition. Commutative property of addition Add –54 and –16. Add –70 and 35. = – (–16 ) – – 16

Use the commutative property to evaluate the expression. Commutative property of multiplication. Multiply 4 and 25. Multiply. 4 (–9) (25) 100 (–9) = (4) (25)(–9) = –900 =

Associative means that the grouping does not make any difference. (a + b) + c = a + (b + c) (ab) c = a (bc) Examples (1 + 2) + 3 = 1 + (2 + 3) (2 3) 4 = 2 (3 4) The associative property does not work for subtraction or division.

Associative property of addition. Add fractions. Add. Use the associative property to evaluate the expression. Write as one.

Using the Associative Property Commutative property of multiplication. Associative property of multiplication. Multiply inside grouping symbols. Multiply.

Any number added to its opposite is always zero. Examples: 5 + (-5) = = 0

20 + (6 – 20) Use properties to evaluate the expression. = 20 + [(-20) + 6] = [20 + (-20)] + 6 = = 6 Commutative property of addition. Associative property of addition. Add. Inverse Property of addition.

Any number multiplied by its reciprocal is one. Examples:

Use properties to evaluate the expression. Commutative property of multiplication. Associative property of multiplication. Inverse property of multiplication. Multiply.

Practice: Worksheet