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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
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
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
There are different ways to express multiplication and division.
Multiplication: Different ways to show four times y.4(y)4 • y4y (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/n12 ÷ n
VOCABULARYEvaluate – 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 cm2 Simplify
4 cm
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 revealanswer
Click to revealanswer
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 cm2
12
12
drag the red check to the yellow check to reveal the answer
Frayer Model
Examples Nonexamples
Definition Characteristics
word
Frayer Model
Examples Nonexamples
Definition Characteristics
opposite
numbers that are the same distance from zeroon a number line but inopposite directions
Frayer Model
Examples Nonexamples
Definition Characteristics
integer
the whole numbers and their opposites
whole numbers are 0, 1, 2 ,...
Frayer Model
ExamplesNonexamples
Definition Characteristics
absolute value
a number's distance from zero on the number line
