Download Using Variables - Onondaga Central School District

How to enter the room:
1.
2.
3.
4.
5.
Greet Mrs. King at the door. A good class
begins with mutual respect and recognition.
Retrieve a copy of the notes from the
materials table. Complete “Math on the
Mind” exercises.
Open your binder to the first section
Write today’s date at the top (9/11/2014)
Prepare to take notes
Math on the Mind:
Write an algebraic expression for each phrase.
1. 7 less than 9
9–7
2. the product of 8 and p
8p
3. 4 more than twice c
2c + 4
Define variables and write an equation to model each situation.
4. The total cost is the number of sandwiches times $3.50.
Let c = the total cost and s = the number of sandwiches; c = 3.5s
5. The perimeter of a regular hexagon is 6 times the length of one side.
Let p = the perimeter and s = the length of a side; p = 6s
Exponents
and
Order of Operations
Algebra A
Unit 1, Lesson 2
Definition
Simplify: replace a numerical expression with its
simplest name.
Definition
Exponent: tells how many times a number
(the base) is used as a factor.
Order of Operations

PEMDAS
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction
Example of the “long way”
Simplify 32 + 62 – 14 • 3.
= 32 + 36 – 14 • 3
Simplify the power: 62 = 6 • 6 = 36.
= 32 + 36 – 42
Multiply 14 and 3.
= 68 – 42 Add and subtract in
order from left to right.
= 26
Subtract.
Same Example:
Simplify 32 + 62 – 14 • 3.
= 26
Practice:
Simplify 3(8 + 6) ÷ (42 – 10).
=7
Practice:
Simplify 4[(2 • 9) + (15 ÷ 3)2].
= 172
Practice:
3  5  2   8  2  1
5
9
Definition
Evaluate: substitute a given value for each
variable into an algebraic expression and then
simplify using the order of operations.
Practice:
Evaluate 5x + 32 ÷ p for x = 2 and p = 3.
= 5 • 2 + 32 ÷ 3
Substitute 2 for x
and 3 for p.
= 13
Practice:
Evaluate each expression for x = 11 and z = 16.
a. (xz)2
b. xz2
= (11 • 16)2
= 11 • 162
= 30,976
= 2816
At the end of the lesson:
1.
2.
3.
Make sure your notes are secured in
your binder in the notes section and in
order.
Pay attention for any special
instructions regarding the homework.
Write your name and the date on the
worksheet as soon as you receive a
copy.
Homework
Practice 1-2 worksheet
#1-13