The document provides an agenda for an October 28 math class. It includes a do now, homework check on integers and absolute value using a Frayer model vocabulary template, and homework assignments from a pre-algebra textbook. Expressions are categorized as variable expressions, numerical expressions, or variables. Ways to write multiplication and division are demonstrated, along with examples of evaluating variable expressions by substituting values for variables. Vocabulary on evaluating, integers, opposite numbers, and absolute value are defined using Frayer models.

1. Agenda Oct. 28
DO NOW
Homework Check
Substitution
Integers & Absolute Value - use frayer model vocabulary
templates
Homework 25
PreAl p. 20 # 7 - 15, 22, 24, 26, 31 - 34, 40 - 46
Daily Scribe: Today Tomorrow
Monday Tuesday

2. p. 32 # 32 - 44HW CHECK
32. -49 - 75 = -124
33. -65 - 15 = -80
34. 16 - (-3) = 19
35. 120 - (-50) = 170
36. 989 - 76 = 913
37. -35 - 25 = -60
38. -92 - (-9) = -83
39. -81 - (-13) = -68
40. 36 - 88 = -52
41. -90 - (-80) - 20 = -30
42. 810 - 30 - (-70)=850
43. 23 - (-15) - 28 = 10
44. -17 + 25 - (-58) = 66

3. Sort the expression in the light blue box into one of the three categories.
Variable Variable Expression Numerical Expression
82 + w
g - 6
30/p
17 - 2 + 5
24 + 2 x 4
y
x
k
m 18s
(5 + 9)/7

4. There are different ways to express multiplication and
division.
Multiplication: Different ways to show four times y.
4(y)
4 • y
4y (The number is always written before the variable.)
(4)(y)
4 x y (Try to avoid 4 x y because you may confuse the
variable x and the times symbol x.)
Division: Different ways to show twelve divided by n.
12/n
12 ÷ n

5. VOCABULARY
Evaluate – to evaluate a variable expression, you write the
expression, substitute (replace) a number for each variable, and
simplify.
EVALUATING EXPRESSIONS
What is the Area of this triangle?
A =
1/2bh Variable Expression
A = 1/2(4)
(12) Substitute numbers
for variables
12cm A = 24 cm
2
Simplify
4 cm

6. Example 1: Identify the variable. Evaluate the variable expression when y = 3.
A. 27y B. -12/y + 8
27y -12/y + 8
27(3)
-12/3 + 8
-4 + 8
81
4
Click to
reveal
answer
Click to
reveal
answer

7. Example 2: Find the area of a triangle if the base is 5 cm and the height is 4 cm. Remember to label!
A = (5)(4)
A = (20)
A = 10 cm
2
1
2
1
2
drag the red check to the yellow check to reveal the answer

8. Frayer Model
Examples Nonexamples
Definition Characteristics
word

9. Frayer Model
Examples Nonexamples
Definition Characteristics
opposite
numbers that are the
same distance from zero
on a number line but in
opposite directions

10. Frayer Model
Examples Nonexamples
Definition Characteristics
integer
the whole numbers and
their opposites
whole numbers are
0, 1, 2 ,...

14. Frayer Model
Examples
Nonexamples
Definition Characteristics
absolute value
a number's distance
from zero on the
number line