Download PowerPoint on Equivalent Ratios

EQUIVALENT RATIOS
By, Mrs. Muller
KEY VOCABULARY
Ratio:
A comparison of two quantities by division.

Equivalent:
Same measurement or the same amount


Equivalent Ratio: two ratios that name the same
number
COMPARING FRACTIONS TO RATIOS
Part of
a
whole
They
both
involve
division
Fractions
Can be
written
only one
way
Used to
compare
two
amounts
Ratios
They are
both
simplified by
dividing by
the GCD
Can be
written
3 ways:
4 to 2,
4/2, 4:2
MAKING A TABLE
Tables show how much one amount compares to
another amount at different stages.
 Example: Comparing Students to Computers 5:2


Students
5
10
15
20
40
Computers
2
4
6
8
16
What ever you multiply the top number of the
table by to get the new amount, you must
multiply the bottom number by in order to get its
new amount in order to keep them Equivalent.
EXAMPLES
COMPARING RATIOS
When we compare fractions we are seeing if they
are equivalent.
 When we compare Ratios we are doing the same
thing, we are seeing if they are equivalent.
 By comparing Ratios we are seeing if the
quantities at different amounts are comparable.

HOW TO TELL IF THEY ARE EQUIVALENT
In order to tell you if two ratios are equivalent,
you need to cross multiply and see if the resulting
numbers are equal. If they are equal the two
ratios are equivalent.
 Example:

Are they equivalent?
NON EXAMPLE
Are they equivalent?
SOLVING FOR THE UNKNOWN VALUE OF A
RATIO
Sometimes you know where you want to go, but
not what is needed to get there; this can happen
in a ratio. I know that I want to use a certain
amount of something, but do not know what that
means for the other amount I use.
 https://www.youtube.com/watch?v=6MWTIcPLdg
 In this case I would cross multiply and then solve
for the unknown.

EXAMPLE