1.3 Write Expressions
Goal • Translate verbal phrases into expressions; Review rates/unit rates
VOCABULARY
Verbal model
Rate
Unit rate
TRANSLATING VERBAL PHRASES
Operation
Verbal Phrase
Addition
Subtraction
Expression
The sum of 3 and a number n
A number x plus 10
_______________
_______________
_______________
The difference of 7 and a number a
_______________
Twelve less than a number x
Order is important when writing subtraction and division
expressions.
Multiplication
Division
Five times a number y
The product of 2 and a number n
_______________
The quotient of a number a and 6
_______________
Eight divided into a number y
_______________
Example 1 - Translate verbal phrases into expressions
Verbal Phrase
a) 6 less than the quantity 8 times a number x
_____________
Expression
_______________
The words “the quantity” tell you what to group when translating verbal phrases.
b) 2 times the sum of 5 and a number a
_______________
c) The difference of 17 and the cube of a number n
_______________
Now You Try It ! Translate the verbal phrase into an expression.
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2) The quotient of 10 and the quantity of a number x minus 3.
1 1) The product of 5 and the quantity 12 plus a number.
Example 2 - Use a verbal model to write an expression
Food Drive you and three friends are collecting canned food for a food drive. You each collect the
same number of cans. Write an expression for the total number of cans collected.
Write a verbal
______________________________ × ____________________________
model.
Translate the
_____
×
_____
verbal model
into an algebraic
expression.
An expression that represents the total number of cans is ________.
Step
1
Step
2
Now You Try It ! Complete the following exercise.
3) In Example 2, suppose that the total number of cans collected are distributed equally to 2 food
banks. Write an expression that represents the number of cans each food bank receives.
Example 3 - Find a unit rate
Three gallons of milk cost $9.15. Find the unit rate.
1. Decide what you are comparing (do we want to know gallons per cent or cents per gallon).
2. Write the comparison as a rate.
3. Reduce to a unit rate.
Now You Try It! Find the unit rate. In some cases, use the unit rate to solve the
problem.
4) Jim traveled for 3 hours and covered 420 miles. Write a unit rate to show his speed.
5) Sam had a recipe for punch that calls for 20 cups of 7-up for every eight people what you want
to serve. Write the unit rate. Use the unit rate to decide how many cups would be required for
12 people.
2 $12
3 ft 2
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6) Write the unit rate: