Transcript Do Now

Do Now
“It depends on the age of the kid, but I think the
formal ratio is three practices to one game,” Hugo
Grajeda says (TFK 6/14).
1) If a soccer season included 16 games, how many
practices should the team have? If there were 27
practices, how many games were held?
2) $2.6 billion is the expected amount of spending on
Halloween costumes. Write in standard form.
3) The total amount expected to be spent on candy is
about $2 billion. The ratio of $ spent on candy to
total spent on Halloween in 2013 is 1:4. About how
much was spent in 2013 for Halloween?
Do Now
Find the missing value in each ratio.
6 = __
18
1. __
t = 15
6
42
__
__
2. 8 = n
n = 56
t
45
21
x
__
__
3.
=
11
44
x = 84
10/28/2014 3-3 C Ratio and Rate Problems
Happy Birthday Mr. Coulter!
Method1. equivalent ratios
2. proportions using multiplication and division
2
__
1
=
4
__
2
• scale drawing- represent objects that are too
large or too small to be drawn to actual size
• scale- the ratio of a length on a drawing or
model to its actual length
Ex. 1:
Find the distance between Canberra & Mackay.
The distance between
the 2 cities is about 2.5
cm. Solve using the
scale 1 cm = 400 mi.
The distance is about 400 (2.5) = 1,000 miles.
Ex. 2:
Find the distance between PPB & Forked River.
The distance between
the 2 towns is about
2.75 in. Solve using the
scale 1 in = 10 mi.
The distance is about 10
(2.75) = 27.5 miles.
Example 3
Pine Hill Middle School has 300 students. In Zoey’s class,
two out of five students belong to a club. Use this ratio
to predict how many students at Pine Hill Middle School
belong to a club.
in a club
total
2
___
5
=
?
_____
300
in a club
total
We can predict that 120 students belong to a club.
Example 4
In a survey, the ratio of students who prefer soccer to
baseball is 2 to 3. The number of people who prefer
soccer is 36. How many people in the survey prefer
baseball?
Or use equivalent fractions
(proportions)
2
___
soccer
baseball
3
=
36
_____
?
×18
2
___
3
=
36
_____
54
Since 2  18 = 36,
multiply 3 by 18.
×18
54 people in the survey prefer baseball.
soccer
baseball
Example 5
There are 57 ounces of dog biscuits in 5 boxes. At this
rate, how many ounces of dog biscuits are in 8 boxes?
÷5
57 ounces
____________
5 boxes
=
? ounces
___________
57 ounces
____________
1 box
5 boxes
÷5
11.4 ounces
______________
1 box
× 8 boxes = 91.2 ounces
=
11.4
ounces
___________
1 box
Exit Ticket
1.)
In a survey, seven out of ten people preferred apple pie
over other flavors. There are 250 people shopping at the
grocery store. Use the survey to predict how many
people in the store would prefer apple pie.
175 people
2.)
A recipe for lasagna calls for 15 ounces of ricotta cheese
for 12 servings. How many ounces of cheese are needed
for 20 servings?
25 ounces
3.)
A survey found that 5 out of every 8 students would
prefer an earlier lunch period. If 120 students chose an
earlier lunch on the survey, how many students took the
survey?
192 students
Homework
1) Pg. 183 #1-22 Evens
2) Ch. 3 Test on Thursday
3) Ch. 3 Quiz Corrections due Monday (11/3)