Objective: To understand how to prove fractions are
equivalent.
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Equivalent Ratios There are different ways to determine if two
ratios or rates are equivalent. 1. Compare unit rates. A unit rate
always has to have a denominator of what?
Slide 4
Equivalent Ratios There are different ways to determine if two
ratios or rates are equivalent. 1. Compare unit rates. A unit rate
always has to have a denominator of what? 1
Slide 5
Equivalent Ratios
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??
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The other way to find if two ratios are equivalent is to set
them equal to each other (proportion)and cross multiply. e.g. 20
miles 45 miles 5 hours = 9 hours
Slide 11
Equivalent Ratios When setting up a proportion the same units
are on top and the same are on bottom. e.g. 20 miles 45 miles 5
hours = 9 hours
Slide 12
Equivalent Ratios The other way to find if two ratios are
equivalent is to set them equal to each other and cross multiply.
e.g. 20 45 5 = 9 5 x 45 = ?
Slide 13
Equivalent Ratios The other way to find if two ratios are
equivalent is to set them equal to each other and cross multiply.
e.g. 20 45 5 = 9 5 x 45 = 225
Slide 14
Equivalent Ratios The other way to find if two ratios are
equivalent is to set them equal to each other and cross multiply.
e.g. 20 45 5 = 9 5 x 45 = 225 20 x 9 = ?
Slide 15
Equivalent Ratios The other way to find if two ratios are
equivalent is to set them equal to each other and cross multiply.
e.g. 20 45 5 = 9 5 x 45 = 225 and 20 x 9 = 180
Slide 16
Equivalent Ratios The other way to find if two ratios are
equivalent is to set them equal to each other and cross multiply.
e.g. 20 45 5 = 9 Does 225 = 180 ?
Slide 17
Equivalent Ratios The other way to find if two ratios are
equivalent is to set them equal to each other and cross multiply.
e.g. 20 45 5 = 9 225 180, they are not equivalent.
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Equivalent Ratios Use either method.
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Equivalent Ratios ??
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Do this on your own.
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Equivalent Ratios 90 x 3 = 270 and 45 x 6 = 270 270 = 270 They
are equivalent.
Slide 25
Equivalent Ratios Is this a true statement? 5 2 6 = 3
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Equivalent Ratios Is this a true statement? 5 2 6 = 3 Does 5 x
3 = 6 x 2?
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Equivalent Ratios Is this a true statement? 5 2 6 = 3 Does 5 x
3 = 6 x 2? 15 12 It is not a true statement.
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Equivalent Ratios Solve the proportion. 3 6 4 = m
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Equivalent Ratios Solve the proportion. 3 6 4 = m 3m
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Equivalent Ratios Solve the proportion. 3 6 4 = m 3m = 24
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Equivalent Ratios Solve the proportion. 3m 24 3 = 3 m = 8
Slide 32
Equivalent Ratios Solve the proportion. d 3 16 = 8 Do this on
your own.
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Equivalent Ratios Solve the proportion. d 3 16 = 8 8d 48 8 = 8
d = 6
Slide 34
Equivalent Ratios Solve the proportion. 34 2 x = 4 Do this on
your own.
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Equivalent Ratios Solve the proportion. 34 2 x = 4 136 2x 2 = 2
68 = x
Slide 36
Equivalent Ratios On a recent Saturday Mike rode 42 miles in 3
hours in the morning. In the afternoon he rode 56 miles in 4 hours.
Are these equivalent ratios?
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Equivalent Ratios On a recent Saturday Mike rode 42 miles in 3
hours in the morning. In the afternoon he rode 56 miles in 4 hours.
Are these equivalent ratios? 42 miles 56 miles 3 hours = 4 hours
Remember When setting up a proportion, the same units must be on
the top and the same units must be on the bottom.
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Equivalent Ratios On a recent Saturday Mike rode 42 miles in 3
hours in the morning. In the afternoon he rode 56 miles in 4 hours.
Are these equivalent ratios? 42 miles 56 miles 3 hours = 4 hours 3
x 56 = 42 x 4 168 = 168 They are equivalent
Slide 39
Equivalent Ratios Three out of five students in the first row
made corrections on the last test. Fifteen out of 20 total students
in the class made test corrections. Are these equivalent ratios? Do
this on your own.
Slide 40
Equivalent Ratios Three out of five students in the first row
made corrections on the last test. Fifteen out of 20 total students
in the class made test corrections. Are these equivalent ratios?
3test corrections 15 test corrections 5 total = 20 total 5 x 15 = 3
x 20 75 60 They are not equivalent.
Slide 41
Equivalent Ratios A scale model of a house has a scale of 1
inch = 2.5 feet. If the width of the house on the model is 12
inches, what is the actual width of the house? Do this on your
own.
Slide 42
Equivalent Ratios A scale model of a house has a scale of 1
inch = 2.5 feet. If the width of the house on the model is 12
inches, what is the actual width of the house? 1in 12in 2.5 ft = x
ft x = 12 (2.5) ft x = 30 ft
Slide 43
Equivalent Ratios On a map of Arizona, the distance between
Meadview and Willow Beach is 14 inches. If the scale on the map is
2 inches = 5 miles, what is the actual distance between Meadview
and Willow Beach? Do this on your own.
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Equivalent Ratios On a map of Arizona, the distance between
Meadview and Willow Beach is 14 inches. If the scale on the map is
2 inches = 5 miles, what is the actual distance between Meadview
and Willow Beach? 2in 14in 5mi = x mi 2x = 70 2 2 x = 35
Slide 45
Equivalent Ratios Agenda Notes Homework Homework Practice 2-6
Due Thursday, March 13 You can use a calculator, but show all
work!