Pre-Algebra
Monday August 25
Learning Target
I will be able to recognize and
represent proportional
relationships between
quantities.
What did we do last time?
In problem 1.2 we scaled up and scaled down recipes.
What is the example of scaling up that we talked about?
• scaled up our recipes to make 240 – ½ cup servings
What is the example of scaling down that we talked
about?
• scaled down our recipes to make one cup of juice.
What does part to part mean in our recipes?
What does part to whole mean in our recipes?
Problem 1.3- Think about the
problem
The recipes in the orange juice problem were
written in cans. Could we have written the
recipe in ounces instead?
If each can holds 12 ounces how many ounces
do we need for the Mix A recipe?
2 cans of concentrate
3 cans of water
5 total cans
5 x 12 = 60 ounces
Problem 1.3
In problem 1.2 we used ratios to determine
which recipe was the most “orangey”. Here are
two ratios describing Mix A
two cups of concentrate
to
three cups of water
2:3 or 2/3
This ratio is a part-to-part
ratio. It compares one
part – the water to the
other part – the
concentrate.
OR
two cups of concentrate
to
five cups of juice
2:5 or 2/5
This ratio is a part-towhole ratio. It compares
one part – the
concentrate to the whole
mixture.
Converting units – customary units
http://www.brain
pop.com/math/nu
mbersandoperatio
ns/customaryunits
/
So how can we
break down a
gallon?
Converting units continued
Cups to ounces….
How many ounces are in
a gallon?
16 of 8 ounces = 128 ounces!
Problem 1.3 A
http://dashweb.pearsoncmg.com/main.html?r=
14185&p=367
Can of concentrate
Cans of water
Total juice in cans
How many ounces?
1
3
4
Problem 1.3 B1
http://dashweb.pearsoncmg.com/main.html?r=141
85&p=18
5 1/3 cans
5
x 12 = 60
1/3 x 12 = 4
TOTAL
64 ounces
64 ounces = ½ gallon
Problem 1.3 B2
Which of these containers should you use for
one batch of the lemonade?
Problem 1.3 C. 1b
Cece is making orange juice using one 16 ounce
can of of concentrate. She is using the standard
ratio of one can of concentrate to three cans of
cold water. How large a pitcher will she need?
Problem 1.3 C. 1b
Olivia has a one-gallon pitcher to fill (to the top)
with orange juice. She uses the standard ratio of
one can of concentrate (16 ounces) to three cans of
cold water. How much concentrate does she need?
Standard ratio
3 cans of cold water
1 can of concentrate
4 cans of juice
Problem 1.3 D
Otis likes to use equivalent ratios. For Olivia’s
problem in Question c, part (1), he wrote ratios
in fraction form:
1. What do the
numbers 1, 4 and 128
mean in each ratio?
2. How can Otis find
the correct value of x?
Rate your learning
I will be able to recognize and
represent proportional
relationships between
quantities.