FRACTIONS TO RATIOS
We use ratios to make comparisons between two things. When we express ratios in words,
we use the word "to" -- we say "the ratio of something to something else". Ratios can be
written in several different ways.
Multiplying or dividing each term by the same nonzero number will give an equal ratio. For
example, the ratio 2:4 is equal to the ratio 1:2. To tell if two ratios are equal, use a calculator
and divide. If the division gives the same answer for both ratios, then they are equal.
LENGTH is measured in the basic unit of METERS.
VOLUME is measured in the basic unit of LITERS.
WEIGHT is measured in the basic unit of GRAMS.
The metric system is ordered greatest to smallest. An easy way to
remember the order is:
King Henry Doesn’t Understand Doing Conversions of Metric.
Kilo
Hecta
Deka
Unit:
Liter, Gram, Meter
Deci
Centi
Milli
Use the ladder to change the size of the unit.
Example:
K
H
D
U
D
C
M
Metric Conversions are changing a basic unit into a different size. An example
of metric conversion is changing a millimeter into a centimeter.
Convert:
2000 mg =
g – on the ladder, grams are 3 places to the left of milligrams. You should
move the decimal 3 places to the left to find the measurement. 2000 mg = 2.000 g.
104 km=
m
480 cm=
m
5.6 kg=
g
8 mm=
cm
FRACTION/RATIO PRACTICE
Pharmacy Students NO CALCULATOR
Vet Tech Students May Use a Calculator.
Reduce the ratios to their simplest term.
1.
2.
10:40 =
5:25 =
Convert the ratio to a percent.
5. 1:8 =
6. 2:5 =
3. 111:148 =
4. 200:225 =
7.
3:6 =
8. 12:72 =
Determine the value of X to make the following true proportions.
Round answers to the nearest tenth.
9.
10.
11.
12.
14.5 mg : 4 mL = 25 mg: X mL
2.3 mL : 17.8 mg = 3.7 mL : X mg
150 mg : 2 g = X mg : 5 g
20000 mg : 2 mL = X mg : 5 mL
Convert the following to the equivalent ratio.
13. 25%
14. 12.5%
15. 10%
16. 40%
17. 66%
18. 87.5%
Which is the largest ratio in each problem?
19. (a) 2:5
20. (a) 1:3
(b) 1:6
(b) 7:8
(c) 2:3
(c) 2:7
(d) 1:10
(d) 15:32
(e) 1:4
(e) 1:8
(c) 4:5
(c) 2:5
(d) 13:20
(d) 11:20
(e) 2:3
(e) 6:9
Which is the smallest ratio?
21. (a) 1:12
22. (a) 16:32
(b) 1:6
(b) 2:7
ANSWER KEY
FRACTION/RATIO PRACTICE
Pharmacy Students NO CALCULATOR
Vet Tech Students May Use a Calculator.
Reduce the ratios to their simplest term.
1.
2.
10:40 = 1:4
5:25 = 1:5
Convert the ratio to a percent.
5. 1:8 = 12.5%
6. 2:5 =
40%
3. 120:165 = 24:33
4. 200:225 = 8:9
7.
3:6 =
50%
8. 12:72 = 16.6%
Determine the value of X to make the following true proportions.
Round answers to the nearest tenth.
9.
10.
11.
12.
14.5 mg : 4 mL = 25 mg: X mL X=6.9
2.3 mL : 17.8 mg = 3.7 mL : X mg
X=28.6
150 mg : 2 g = X mg : 5 g
X=375
20000 mg : 2 mL = X mg : 5 mL X=50,000
Convert the following to the equivalent ratio.
13. 25% =1:4
14. 12.5% =1:8
= 15. 10% =1:10
16. 40% =2:5
17. 66% =2:3
18. 87.5% =7:8
Which is the largest ratio in each problem?
19. (a) 2:5
20. (a) 1:3
(b) 1:6
(b) 7:8
(c) 2:3
(c) 2:7
(d) 1:10
(d) 15:32
(e) 1:4
(e) 1:8
(c) 4:5
(c) 2:5
(d) 13:20
(d) 11:20
(e) 2:3
(e) 6:9
Which is the smallest ratio?
21. (a) 1:12
22. (a) 16:32
(b) 1:6
(b) 2:7