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A ratio is the
comparing of two quantities.
A
proportion is an equation with a ratio
on one side and an equal ratio on the other.
2/5 = 4/10 is an example of a
proportion
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Finding equal
ratios |
| One way is to
use multiplication.
Multiply each term by the same
nonzero number will give an equal ratio.
3 x 2 = 6
3 x 3 = 9
3 x 4 =
12
4 x 2
8
4 x 3 12
4 x 4 16
So,
3 6
9 12
4 , 8 , 12 ,
16 are all equal
ratios.
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| Another way
is to use division.
Divide each term by the same
nonzero number will give an equal ratio.
Remember: when you divide you must select a number by which
both terms are divisible.
6
¸
2 = 3
6 ¸
3 = 2
6 ¸
6 =
1
12 ¸
2
6 12
¸
3
4
12 ¸
6
2
So,
3 2
1
6 , 4 , 2
are all equal ratios.
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Ratios
can be written
3 different ways
A ratio of
3 boy to 6 girls
can look like:
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3 to 6 |
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3 : 6 |
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3 /
6
To create equal ratios
for 3 : 6 just multiply or divide both terms by the same nonzero
number. Remember: when you divide you must select a number by
which both terms are divisible.
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Multiply |
Divide |
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3 x 2 = 6
6 x 2 = 12
3 : 6 = 6
: 12
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3/3 = 1
6/3 = 2
3 : 6 = 1
: 2
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So,
1 : 2, 3 : 6,
and 6 : 12
are all equal ratios. |
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Example:
If there were 5 footballs and 2 baseballs
The ratio would be---
5 to 2
it could also look like
5 : 2 or 5
/ 2 The number
of footballs
MUST BE
listed first
To create equal ratios for 5 :
2 just multiply or divide both terms by the same nonzero number. Remember:
when you divide you must select a number by which both terms are divisible.
5 : 2, 10 : 4, and 15 : 6 are all equal ratios. |
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