Transcript Signed Number Operations

Order of Operations
Does the order in which operations are
done make any difference?

Ex. Which is the correct answer when
simplifying 6 + 3 x 12?
6+3x12
6+3x12
=9x12
=108
OR
=6+36
=42
What Rule Do These Examples Seem
to Follow?
8  4  3  20
12  6  2  9
6  5  2  28
PEMDAS (Please Excuse My Dear Aunt Sally)
Parenthesis
 Exponents
 Multiplication/Division
 Addition/Subtraction

Now you try, using the rule…
10  2  3
A: 16
18  6  2
A: 15
8  54
A: 28
48  6  2
A: 16
5 1 10
 
8 5 8
7
A:
8
 8  5  7  8
A: -96
32  5
3
2
A: -1
 10 x 2  20  2
2
A: -15
A=9
Grouping Symbols

Grouping symbols such as parentheses
( ), brackets [ ], and braces are used to
clarify or change the order of operations.

They indicate that the expression within
the grouping symbol is to be evaluated
first.
A: 31
A: 60
A: 36
Fraction Bar

A fraction bar is another type of grouping
symbol.

It indicates that the numerator and
denominator should each be treated as a
single value.
A: 2
A: 1
You Try…..

A: 14
A: 51
A: 60
A: 26
A: 5
Evaluating Algebraic Expressions

First replace the variables with their values.

Then, find the value of the numerical
expressions using the order of operations.
A: 42
A: 30
Evaluate the following if g = 4, h =
6, j = 8, and k = 12.

A: 30
A: 160
A: 1
Evaluate the following if x = 2, y =
3, a = 4/5, and b = 3/5.

A: 9
A: 1
Evaluate the following if x = 2, y =
3, a = 4/5, and b = 3/5.

Evaluate the following if x = 2, y =
3, a = 4/5, and b = 3/5.

Use Algebraic Expressions

Draw diagrams when possible.

Write an expression that represents what the
question is asking you to find.
Order of Operations
Using Signed Numbers
a) 12 + (-7)(2)
= 12 + (-14) = -2
Find the value of y for x= -4
b) y= -17-3x
= -17 – 3(-4) = -17 +12 = -5
Find the value of y for x=4
c) y= 7-2x
= 7 – 2(4) = 7 – 8 = -1
Find the value of y for x=-2
= 7 – 3(-2) = 7 +6 = 13
d) y= 7-3x