Download Vocabulary # 3 (Ratios and Proportions)

7 Math Vocabulary # 3 (Ratios and Proportions).notebook
7th Grade Math Vocabulary
Ahrens
Constant of Proportionality A constant ratio (unit rate) in any proportional relationship
Equations:
Ratios and Proportions (3 , 45)
y = 5 x
k = y x
Ratios and Proportions Glossary
y
x
y = kx
or k = 5
y = kx
45 = k3
k = 15
Constant of Proportionality Equivalent Ratios
Equivalent Ratios
Ratios that have the same value
Two ratios that have the same value, even though they represent different amounts.
3
6
=
1
2
=
4
8
4 12
4 1
=
4 3
Disagree
Ratio
1out of 3
Ratio A comparison of two or more values. Can be written as a fraction, decimal, percent, or with a colon, the word "to" or the words "out of".
4 out of 5
4 to 1
4
5 .8 4:1
80%
is equivalent to
is equivalent to
Equivalent Ratios
Ratio
Agree
10 to 25
= 2 to 5
Equivalent Ratios Dr. Opinions
3 out of 9
1 out of 5
1 to 4
1
5 .2 1:4
20%
A comparison of two numbers by division 3 different ways:
"the ratio of a to b"
a to b
a : b a
b 20 to 48
There are 48 animals in the field. Twenty are cows and the rest are horses. What is the number of cows to the total number of animals?
20:48
20
48
Ratio 1
7 Math Vocabulary # 3 (Ratios and Proportions).notebook
Ahrens
Rate
Rate A ratio that compares quantities in different units.
A ratio of two quantities measured in different units
One minute for every 60 seconds.
min 1
2
3
$8 per adult movie ticket.
sec 60 120 180
adults 1
$
2
3
8 16
24
Expect to drive 35 miles for every hour you drive.
3 participants/2 teams
7 burgers/2 tomatoes
5 gallons/3 rooms
Rate
Rate
Unit Rate
Unit Rate A comparison of two measurements when one of the terms has a value of 1.
Rate with a denominator of one
One minute for every 60 seconds.
1 min:60 sec
$8 per adult movie ticket.
$8
1 adult
35 miles per 1 hour
62 words/minute
34 miles/gallon
3 cookies per person
Unit Rate
Unit Rate Proportion Part to Part Ratio
An equation that states that two ratios are equivalent
A comparison of part of a whole to the rest of the whole.
14
2
=
3
21
1
20
=
2
40
Proportion 5 x3 15
=
8 x3 x
x = 24
1
―
8
3:5
1
―
8
1
―
8
1
―
8
1
―
8
1
―
8
1
―
8
1
―
8
red:white
red
white
3
5
Part to Part Ratio
2
7 Math Vocabulary # 3 (Ratios and Proportions).notebook
1
―
8
Part to Whole Ratio
Percent
A comparison of part of a whole the total.
A ratio which is always based on the total being 100. When broken down, percent means out of 100.
3:8
1
―
8
1
―
8
1
―
8
1
―
8
1
―
8
1
―
8
Ahrens
3
8
red:total
1
―
8
red
total
Per = out of
25%
1 =1/100
Cent = 100
25
100
.25
or one hundredth
$.01
Part to Whole Ratio
Percent
Conversion Factor
Simplest Form
A number used to multiply or divide a quantity to convert from one system of measurement to another. When the GCF of both parts of a ratio is one.
21 days = 3 weeks
To convert days into weeks, divide by 7.
Qts Pts
16 in
12
1.5 ft
Divide by 2
4 12
4 1
=
4 3
3 out of 9
10 to 25
is the same as
1out of 3
Both are divisible by 5
9 qts = 8.5 pts
= 2 to 5
Conversion Factor
Simplest Form
Similar Scale Two shapes that are the same shape but different sizes
The ratio of a drawing to the real life measurement congruent
drawing real life (actual)
:10 ­ 1
Scale
not similar!
Drawn Horse 150mm high
Real Horse 1500mm high
Similar Scale 3
7 Math Vocabulary # 3 (Ratios and Proportions).notebook
Ahrens
Population Density A unit rate of people per square mile
NJ = 8,791,894 people
NJ = 7,790 square miles
Population
Area
Population
Area
=
8,791,894
7,790
= 1,129 people per square mile
Population Density 4