Lesson 1.2 Interpreting Variables EQ: How do I interpret the variable from a word problem? (Standard...
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Les 1.2 Inter pret ing Variables EQ: How do I interpret the variable from a word problem? (Standard A.SSE.1)
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Transcript of Lesson 1.2 Interpreting Variables EQ: How do I interpret the variable from a word problem? (Standard...
Lesson 1.2
Interpretin
g Variables
EQ: How do I interpret the variable from a word problem? (Standard A.SSE.1)
ReviewLast 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 PracticeDirections: Write the expression that represents the statement.
Example 1: Joan’s temperature increased by 3 degreesWhat 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.
