1. 1.6 The Price Is…Close Using Unit Rates in Real World Applications
WARM UP
January 11, 2016
A dozen apples cost $4.99.
A model of this situation is shown.
What does each small rectangle represent?
How many small rectangles are in the model?
What does the largest rectangle represent?
How can you estimate the cost of one apple?
Circulate and see what kids have for this. Make sure that they are able to create some sort of ratio. There is no need to go over this as a class since they will be doing a similar one in the beginning of today’s lesson. Just use it as a quick formative assessment. Address student misconceptions in Problem 1, #1.

2. 1.6 The Price Is…Close Using Unit Rates in Real World Applications
Lesson Opener as a class.
Read the Lesson Opener as a class.

3. 1.6 The Price Is…Close Using Unit Rates in Real World Applications
Problem 1: A Special on Unit Rates in Aisle 9
Marta and Brad go to the store to buy some laundry detergent for a neighbor. They see that the brand he wants comes in two different sizes:
26 fluid ounces for $9.75 and
20.5 fluid ounces for $7.50
Which one should Marta and Brad buy?
Explain the reason for your decision.
Have 4 students come up to draw on whiteboard. Do this as whole class.
2. Which is the better buy? How do you know?

4. 1.6 The Price Is…Close Using Unit Rates in Real World Applications
Problem 1: A Special on Unit Rates in Aisle 9
One way to compare the values of products is to calculate the unit rate for each item.
Marta estimated the unit rates this way:
Have 4 students come up to draw on whiteboard. Do this as whole class.

5. 1.6 The Price Is…Close Using Unit Rates in Real World Applications
Problem 1: A Special on Unit Rates in Aisle 9
Brad estimated the unit rates this way:
Have 4 students come up to draw on whiteboard. Do this as whole class.

6. 1.6 The Price Is…Close Using Unit Rates in Real World Applications
Problem 1: A Special on Unit Rates in Aisle 9
Do #3-5 with
your group.
(pg 53-54)
3 min.
3. Marta and Brad both chose the second one as the better buy, but which one of them reasoned correctly?
They both calculated the unit rates correctly.
Marta - $$ per fluid ounce
Brad – fluid ounces per $$
*Brad drew his model incorrectly
Have 4 students come up to draw on whiteboard. Do this as whole class.
4. Calculate the unit rates for each of these products.
Larger size: $0.38 per fl. oz OR 2.67 fl. oz. per dollar
Smaller size: $0.37 per fl. oz OR 2.73 fl. oz. per dollar
5. Using the unit rates, is it now possible to decide which is the better deal?

7. 1.6 The Price Is…Close Using Unit Rates in Real World Applications
Problem 1: A Special on Unit Rates in Aisle 9
Do #6 a-d with
your group.
(pg 54)
You have 3 min.
Calculate the unit rates for each item.
a. A bottle of 250 vitamins costs $12.50
$0.05 per vitamin or 20 vitamins per dollar
b. A pack of 40 AAA batteries costs $25.95
$0.65 per battery or about 1.5 batteries per dollar
c. A package of 24 rolls of toilet paper cost $16.25
Have 4 students come up to draw on whiteboard. Do this as whole class.
$0.68 per roll or about 1.5 rolls per dollar
d. A box of 500 business cards cost $19.95
$0.04 per card or about 25 cards per dollar

8. 1.6 The Price Is…Close Using Unit Rates in Real World Applications
Problem 1: A Special on Unit Rates in Aisle 9
Do #7 and 8 with your group.
(pg 55)
You have 3 min.
7. Estimate the unit rates to determine which is the better buy.
a. 22 vitamins for $1.97 or 40 vitamins for $3.25
40 vitamins is the better deal since
9 cents per vitamin or 10 cents per vitamin
Have 4 students come up to draw on whiteboard. Do this as whole class.
b ounces for $8.76 or 32.6 ounces for $16.95
24.3 ounces is the better deal since
$0.36 per ounce for 24.3 oz bottle
versus
$0.50 per ounce for 32.6 oz bottle

9. 1.6 The Price Is…Close Using Unit Rates in Real World Applications
Problem 1: A Special on Unit Rates in Aisle 9
Have 4 students come up to draw on whiteboard. Do this as whole class.
0.39:12
$0.0325/oz
0.57:24.3
$0.0235/oz
0.70:33.8
$0.0207/oz
1.39:128
$0.0109/oz
Bottle 4 is the best buy because the price per bottle is lowest.

10. 1.6 The Price Is…Close Using Unit Rates in Real World Applications
Check for Students’ Understanding
Do on your own
You have 3 min.
Have 4 students come up to draw on whiteboard. Do this as whole class.

11. 1.5 Looks can be deceiving! Using proportions to solve problems
Homework:
Weekly Math #16 – Monday
Quiz Tuesday – do RP1 Quiz Practice
Have 4 students come up to draw on whiteboard. Do this as whole class.