2. Do Now 9/15/11 Take out HW from last night. Take out HW from last night.  Text p. 17, #1-4 Copy HW in your planner. Copy HW in your planner.  Text p. 20, #10-36 evens, #40 & 41  POTW#1 In your journal, list as many examples that you can of quantities (numbers in real-life) that change. Then make a second list of quantities that never change. Use examples from your own life. In your journal, list as many examples that you can of quantities (numbers in real-life) that change. Then make a second list of quantities that never change. Use examples from your own life.

3. Text p. 17, #1-4 all Homework Text p. 17, #1-4 all 1). 3 x 2 = 6 hours 2). 18 ÷ 3 = 6 students 3). 48 ÷ 4 = 12 percussion instruments 4). 7 x 4 = 28 students

4. Objective SWBAT evaluate variable expressions.

5. Variable a letter used to represent one or more numbers. a e m k y s t Section 1.3, “Variables and Algebraic Expressions” Section 1.3, “Variables and Algebraic Expressions”

6. Constant a number in an expression that does not change.

7. Algebraic expression consists of one or more variables, operations, and constants. 9 + a e ÷ 6 3m 2k - 7 y – 7 3t + 2y

8. substitute a number for each variable, perform the operations and simplify, if necessary. To EVALUATE A VARIABLE EXPRESSION- Substitute 3 for n. Multiply. 13· n 13· 3 39

9. Evaluate the Expression PEMDAS 4(3) + 2 12 + 2 14 14 4x + 2 x = 3 Substitute

10. Evaluate the Expression PEMDAS x 3 + 2(4) + 2(4) 1 + 8 9 x = 3 and y = 4 Substitute + 2y 3 3

11. Evaluate the Expression PEMDAS 4(3 + 5) 4(8) 32 32 4(x + y) x = 3 and y = 5 Substitute

12. Evaluate the Expression PEMDAS 3(2 + 5) 3(7) 3(49) 3(49) 3(x + y) x = 2 and y = 5 Substitute ² ² ² 147 147

13. Evaluate the Expression PEMDAS 12 – x 6y Grouping symbol (6 · 5) ÷ (12 – 2) 30 ÷ 10 3 x = 2 and y = 5 Substitute

14. Evaluate the Expression [w(x + z)] + y PEMDAS [3 · 10] + 2 30 + 2 38 ³ ³ ³ 30 + 8 [3 · (4 + 6)] + 2 ³ w = 3, x = 4, y = 2, & z = 6

15. Evaluate the Expression 5x + z PEMDAS 5 · 16 + 6 80 + 6 86 86 ² 5(4) + 6 ² x = 4, z = 6

16. Text p. 20, #10-36 evens, #40 & 41 Homework 24