Transcript Lesson 1 MI/Vocab

• Express ratios as fractions in simplest form and
determine unit rates.
• ratio
• rate
• unit rate
Write Ratios in Simplest Form
Express 12 blue marbles out of 18 marbles in
simplest form.
Divide the numerator and
denominator by the greatest
common factor, 6. Divide
out common units.
Answer:
Express 5 blue marbles out of 20 marbles in simplest
form.
A.
B.
A
0%
B
C
D
D
0%
B
D.
A
0%
A.
0%
B.
C.
D.
C
C.
Write Ratios in Simplest Form
Express 10 inches to 2 feet in simplest form.
Convert 2 feet to 24 inches.
Divide the numerator and
denominator by 2. Divide
out common units.
Answer:
Express 14 inches to 2 feet in simplest form.
A.
B.
0%
C.
D.
1.
2.
3.
4.
A
B
C
D
A
B
C
D
Find a Unit Rate
READING Y-Mei reads 141 pages in 3 hours. How
many pages does she read per hour?
Write the rate that expresses the comparison of pages
to hours. Then find the unit rate.
Divide the numerator and
denominator by 3 to get a
denominator of 1.
Answer: Y-Mei reads an average of 47 pages per hour.
TRAVEL On a trip from Columbus, Ohio, to Myrtle
Beach, South Carolina, Lee drove 864 miles in 14
hours. What was Lee’s average speed in miles per
hour?
A. about 57 mph
0%
B. about 60 mph
C. about 62 mph
1.
2.
3.
4.
A
B
C
D
A
D. about 65 mph
B
C
D
Compare Unit Rates
SHOPPING Alex spends $12.50 for 2 pounds of
almonds and $23.85 for 5 pounds of jellybeans.
Which item costs less per pound? By how much?
For each item, write a rate that compares the cost of the
item to the number of pounds. Then find the unit rates.
Answer: The almonds cost $6.25 per pound, and the
jellybeans cost $4.77 per pound. So, the
jellybeans cost $6.25 – $4.77 or $1.48 per
pound less than the almonds.
SHOPPING Cameron spends $22.50 for 2 pounds of
macadamia nuts and $31.05 for 3 pounds of cashews.
Which item costs less per pound? By how much?
A. cashews by $0.90
B. cashews by $1.25
D
A
0%
B 0%
C
D
C
D. macadamia nuts by $1.25
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0%
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0%
B.
C.
D.
B
C. macadamia nuts by $0.90
• Identify proportional and nonproportional
relationships.
• proportional
• nonproportional
Identify Proportional Relationships
HOUSE CLEANING A house-cleaning service
charges $45 for the first hour and $30 per hour for
each additional hour. The service works for 4 hours.
Is the fee proportional to the number of hours
worked? Make a table of values to explain your
reasoning.
Find the fee for 1, 2, 3, and 4 hours worked and make a
table to display numbers and cost.
Identify Proportional Relationships
For each number of hours, write the relationship of the
fee and number of hours as a ratio in simplest form.
,
Answer: Since the ratios of the two quantities are not
the same, the fee is not proportional to the
number of hours worked. The relationship is
nonproportional.
PLUMBING A plumbing company charges $50 for
the first hour and $40 for each additional hour.
Suppose a service call is estimated to last 4 hours.
Is the fee proportional to the number of hours
worked?
A. yes
1.
2.
A
0%
A
B
0%
B
B. no
Identify Proportional Relationships
Find the amount of jelly and egg whites needed for
different numbers of servings and make a table to show
these measures.
Identify Proportional Relationships
For each number of cups of jelly, write the relationship of
the amount of jelly to the number of egg whites as a ratio
in simplest form.
Answer: Since the ratios between the two quantities are
all equal to
, the amount of jelly used is proportional to
the number of egg whites used.
COOKING Among other ingredients, a chocolate
chip cookie recipe calls for 2.5 cups of flour for every
1 cup of sugar and every 2 eggs. Is the amount of
flour used proportional to the number of eggs used?
A. yes
B. no
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A
B
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B
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2.