September 15, 2014
Lesson 1.3: Algebraic Expressions
By the end of this lesson....
1) You will use patterns to describe the world and solve
problems
2)You will represent algebraic expressions in multiple ways
September 15, 2014
Before we start... we need to go over some important
terms.
Algebraic Expression - a mathematical
expression containing
a variable
Variable - a letter or symbol representing a
quantity
Numerical Coefficient - the number by
which a variable is
multiplied.
Constant: the number in an expression or
equation that does not change.
September 15, 2014
For Example:
In the algebraic expression
7t + 2
7 is the numerical coefficient
2 is the constant term
t is the variable
**Also important to note, this is an EXPRESSION because it does
not have an = sign!
September 15, 2014
Let's Try
In the algebraic expression
x + 2
the numerical coefficient is ____________
In the algebraic expression
x/3 + 2
the numerical coefficient is ____________
September 15, 2014
Quick Check
Elbow Partners
Determine the variable, constant term and numerical
coefficient for the following algebraic expressions
Algebraic
Expression
3x + 4
b/5 + 8
a + 10
Numerical
Coefficient
Constant Term
Variable
September 15, 2014
MathLAB
Groups of 4
When writing an algebraic expression there are some
keywords that gives us a hint for which operation to perform
(+ - x ÷)
Your goal is to take the words on the flashcards and group
them into like concepts
(ones that you think mean the same thing)
Fill in the chart in your notes package, with the math concept
as the title and all the words that relate to that concept
below it.
September 15, 2014
Quick Check
Practice writing algebraic expressions
five more than a number
thee less than a number
three subtract a number
five times a number
three more than five times a number
a number divided by one hundred
one hundred divided by a number
September 15, 2014
Problem Solving
Tehya won some money in a competition. She has two
choices as to how she gets paid.
(There are 52 weeks in a year)
Choice 1: $20.00 per week for one year
Choice 2: 400 cash now plus $12.00 per week for one
year.
1) If Tehya chooses Choice 1, how much will she be paid?
2) If Tehya chooses Choice 2, how much will she be paid?
3) Which method would pay Tehya more money? Explain.
4) Why might Tehya choose the method that pays less?
STOP.... before we start answering these questions,
we need to do some math!
September 15, 2014
Problem Solving
Use Choice 1: How can you calculate the money
Tehya has received after
1 week?
2 weeks?
3 weeks?
6 weeks?
What rule can we write to calculate the money received at
any time during the year for choice 1?
September 15, 2014
Problem Solving
Use Choice 2: How can you calculate the money
Tehya has received after
1 week?
2 weeks?
3 weeks?
6 weeks?
What rule can we write to calculate the money received at
any time during the year for choice 2?
September 15, 2014
REVIEW
Order of Operations
September 15, 2014
Quick Check
Evaluation the following expressions using the order of
operations (BEDMAS)
a) 3 + 4 x 6
b) 5 x 6 - 3 + 9
c) 25/5 - 1
September 15, 2014
Class Notes
Since we know that variables are letter that represent
numbers
to evaluate an expression measure to substitute a number
for the variable.
We then calculate the answer with this number in the
expressions.
EXAMPLE
Evaluate the expression 2a - 5, when a = 7
Step 1: Substitute the variable a with the number 7
2(7) - 5
Step 2: Use order of operations to evaluate
2(7) - 5
14 - 5
9
September 15, 2014
Quick Check
Evaluate the following algebraic expressions:
a) 5n - 4, when n=7
b) 20 - p, when p = 14
c) x/3, when x = 12
September 15, 2014
YOUR TURN
1) Assigned work: Pg. 18 & 19 #2, 3, 6, 7e, 7f, 8f & 9
2) Complete the Assessment Focus Question and have it
checked by Mrs. French
3) Challenge Questions: Pg. 19 #10 b, c & f
(These are questions you need to be able to complete
and understand if you are looking to get honors mark in
Math)