Notes-Ratios and Proportions Lesson 12: Ratios of Fractions and Their Unit Rates
Name _________________________Date _______________Period _____
Example 1: Time to Remodel
You have decided to remodel your bathroom and put tile on the floor. The bathroom is in the
shape of a rectangle and the floor measures 14 feet 8 inches long, 5 feet 6 inches wide. The
tile you want to use costs $5 each, and each tile covers 4 square feet. If you have $100 to
spend, do you have enough money to complete the project?
Make a Plan: Complete the chart to identify the necessary steps in the plan and find a solution.
What I Know
What I Want to Find
Area
How to Find it
1-convert inches to feet as a
fraction over 12
2- A = L •W
Square footage of 1 tile
Number of tiles needed
Cost of 1 tile
Total cost of all tiles
Area of the bathroom divided
by the area of 1 tile
Multiply the total amount of
tiles by the cost of one ($5)
Have $100
Is this enough?
Dimensions of the floor
$100-total money to spend if
the total cost is more than
$100, then there is not enough
money
Work with a partner to follow through on the plan we have created. Focus on what we need to
find and how to find it. Show your work in the boxes below.
Area
Number of Tiles Needed
14 • 5
80 ÷ 4
•
•
÷
=
= 80
square feet
•
•
= 17
Total Cost of All Tiles
18 • 5 = 90
It will cost $90 to buy all the tiles needed to
remodel the bathroom.
Since you have to buy whole tiles, you need 18
tiles.
Is This Enough? Justify
Yes, there is enough money to buy the tiles for
the bathroom. The budget is $100 and the
tiles will cost $90.
Notes-Ratios and Proportions Lesson 12: Ratios of Fractions and Their Unit Rates
Exercise 1
Which car can travel further on 1 gallon of gas? (Hint: compare unit rates). Show and label
your work. The blue car travels farther on 1 gallon of gas than the red car.
Blue car: travels 18 miles using 0.8 gallons of gas
Red car: travels 17
miles using 0.75 gallons of gas
Red car
•
Blue car
•1.25
=
=
•
•1.25
•
•
•
•
•
•
X = 23
23 miles per gallon
X = 21
23 miles per gallon
Lesson Summary:
A fraction whose numerator or denominator is itself a fraction is called a complex fraction.
To reduce a complex fraction, divided the numerator by the denominator, using the division of
fractions rules.
Review: a unit rate is a rate, containing an x per 1 comparison.