1. Chapter 2: Solving One-Step Equations and Inequalities 2.1 Properties of Numbers

2. Properties Commutative property of addition & multiplication: –Changing the order of the values you are adding or multiplying does not change the sum or product

3. Properties Associative properties of addition & multiplication –Changing the grouping of the values you are adding or multiplying does not change the sum or product

4. Example 1 Carlos rented a set of golf clubs for $7 and a golf cart for $12. He paid a greens fee of $23. Find his total cost.

5. Properties Identity properties of addition & multiplication –The sum of any number and zero is the original number –The product of any number and 1 is the original number

6. Example 2 Name each property shown: 5 · 7 = 7 · 5 c · 1 = c 7 + a = a + 7 5(xy) = (5x)y

7. Example 3 Use mental math to simplify: (81 + 6) + 9

8. Example 4 Suppose you buy the school supplies, a highlighter for $.85, an eraser for $.35, and paper for $1.65. Use mental math to find the cost of the supplies.

9. Example 5 Use mental math to simplify: (4 · 9) · 5

10. Example 6 Use mental math to simplify: 5 · 9 · 6 · (-2) · (-1)