Lesson 1.2 ppt - WordPress.com
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Transcript Lesson 1.2 ppt - WordPress.com
EQ: How do I interpret the variable from a word problem?
(Standard A.SSE.1)
Review
Last class, we practiced writing
expressions from word problems.
Today we will work on interpreting the
variable in context of the problem.
What is the variable?
Given an expression or word problem, how
can you determine what the variable
represents?
Questions to ask yourself:
What is the problem asking me?
What information do I know from this
problem?
What is the unknown variable?
What am I trying to solve for?
Creating Expressions Practice
Directions: Write the expression that represents the
statement.
Example 1: Joan’s temperature increased by 3
degrees
What is the unknown variable?
Joan’s temperature
Answer: t + 3
Example 2: Six minutes less than twice Bob’s time
What is the unknown variable?
Bob’s time
Answer: 2b – 6
You Try!
Directions: Write the expression that represents the
statement.
Example 3: Twice Betty’s age plus 5
Example 4: 3 less than 12 times John’s age
Expressions from Word Problems
Example 5: Sara and her friends had dinner at a
Spanish restaurant that charges $6 per tapas. All
of them shared several tapas. The total bill
included taxes of $4.32. Write an algebraic
expression that represents the total cost of the
dinner.
What do I know?
What is the unknown variable?
Answer: 6p + 4.32
What does the variable, p, represent?
p represents the number of tapas ordered.
Expressions from Word Problems
Example 6a: Andre purchased a can of tennis balls
and received a 25% discount. Write an algebraic
expression to represent the total cost of the tennis
balls.
What do I know?
What is the unknown variable?
Answer: t – .25t
What does the variable, t, represent?
t represents the cost of the can of tennis balls
Expressions from Word Problems
Example 6b: What if Andre purchased 10 cans of
tennis balls and still received the same 25% discount.
How would your expression from part a change?
Answer from part a: t – .25t
Expressions from Word Problems
Example 6c: How would your expression from part b
change if Andre had to pay a shipping cost of $5.99?
Answer from part b: 10t – .25(10t)
You Try!
Example 7: Gavin agrees to buy a 6-month
package deal of monthly gym passes, and in turn
receives a 15% discount. Write an algebraic
expression to represent the total cost of the
monthly passes with the discount.