Chapter 5
Units
 Measures the drug in terms of action
No symbol for units
Sample problems - Answers
 Express the unit dosage in numerals and
symbols:
1. Three hundred and fifty thousand units.
A. 350,000 units
2. Twenty-five hundred units.
A. 25,000 units
3. Sixty units.
A. 60 units
Percentage (%) measures
 Percentage means parts per hundred.
 No space between the # and the %
 1% not 1 %
 The greater the percentage
strength, the stronger the solution
or ointment.
Sample Question
Which is stronger, a 3% solution or
a 6% solution?
A. 3%
B. 6%
Which of the following is the correct
abbreviation for “units”?
A. Un
B. U
C. UN
D. Ut
E. None of the above
Percentage (%) measures
 In solution, percent represents the
number of grams of drug per 100 mL
of solution.
 100 mL of a 1% solution will contain 1 g
of drug
Sample Questions
 100 mL of a 1% solution will contain how
many grams of drug?
1 g
 100 mL of a 2.5% solution will contain how
many grams of drug?
 2.5 g
 100 mL of a 10% solution will contain how
many grams of drug?
 10 g
100 mL of a 5% solution will contain
how many grams of drug?
A.1 g
B. 5 g
C. 10 g
D.100 g
E. None of the above
But what if it is not 100 mL
Mrs. Keele?
Convert % to fraction
To change percentage to fraction ÷
by 100
5% = 5 ÷ 100 = 0.05
What is the fraction of 7%
A. 70
B. 7
C. 0.7
D. 0.07
E. 0.007
What is the fraction of 60%
A. 60
B. 6
C. 0.6
D. 0.06
E. None of the above
100 mL of a 5% solution will contain
how many grams of drug?
100 𝑚𝐿 × 5%
5% = 5 ÷ 100 = 0.05g/mL
100 × 0.05 = 5𝑔
250 mL of a 5% solution will contain
how many grams of drug?
250𝑚𝐿 × 5% =
5% = 5 ÷ 100 = 0.05g/mL
250 × 0.05 = 12.5𝑔
325 mL of a 6% solution will contain
how many grams of drug?
A.18.5 g
B. 6 g
C. 16.25 g
D.19.5 g
E. None of the above
120 mL of a 5.4% solution will
contain how many grams of drug?
A. 6.45 g
B. 64.5 g
C. 645 g
D. None of the above
E. I’m so lost I have no idea!
260 mL of a 3% solution will contain
how many grams of drug?
A. 0.78 g
B. 7.8 g
C. 78 g
D. 780 g
E. None of the above
Milliequivalent (mEq) measures
 Number of grams of drug contained in
1 mL of a solution
 Who cares?
 Not you
 What do I need to know
 -mEq = milliequivalent
Sample Questions:
 Express the milliequivalent dosages in
numbers and symbols:
1. Fifteen milliequivalents
A. 15 mEq
2. Twenty-five milliequivalents
A. 25 mEq
3. Forty-two milliequivalents
A. 42 mEq
Ratio Measures
 Parts of drug per parts of solution
 1:500
 1 part drug to 500 parts solution
 1:20
 1 part drug to 20 parts solution
 A solution that is 1 part drug and 10 parts
solution is written:
 1:10
 If I take 1 bottle of alcohol
& add it to 2 bottles of
soda 
 1:2 ratio
 How drunk would one
glass of this spiked
punch make you?
 If I take 1 bottle of
alcohol & add it to 5
bottles of soda
 1:5 ratio
 How drunk would one
glass of this spiked
punch make you?
 Which would make you
more drunk 1:2 or 1:5?
Ratio Measures
 The less solution a drug is dissolved in,
the stronger the solution.
 A ratio of 1:2 is much stronger than
1:5
 A ration of 1:5 is much stronger than
a 1:500
Identify the strongest solution:
A) 1:20
B) 1:200
C) 1:2
Identify the strongest solution:
A) 1:50
B) 1:20
C) 1:100
Identify the strongest solution:
A) 1:1000
B) 1:4000
C) 1:3000
Household & Apothecary measures
 Ounce
 Abbreviation: oz
Household & Apothecary measures
 Ounce
 Metric equivalent: 30 mL
 1 oz = 30 mL
 How many milliliters in 3 oz?
 90 mL
30𝑚𝐿

1𝑜𝑧
× 3𝑜𝑧 = 90 mL
Household & Apothecary measures
 Tablespoon
 Abbreviation: T, TBS, Tbsp
 Metric equivalent: 15 mL
 1 Tbsp. = 15 mL
 How many milliliters in 3 Tbsp?
 45 mL (3 x 15 = 45)
15𝑚𝐿

1𝑇𝑏𝑠𝑝.
× 3𝑇𝑏𝑠𝑝 = 45mL
Household & Apothecary measures
 Teaspoon
 Abbreviation: t, TSP, tsp
 Metric equivalent: 5 mL
 So 1 tsp = 5 mL
 How many milliliters in 3 tsp?
 15 mL (3 tsp x 5 mL = 15 mL)
Household & Apothecary measures
 Drop
 Abbreviation: gtt (gtts)
 Metric equivalent: 1 mL
 So 1 gtt = 1 mL
 How many milliliters in 3 gtts?
 3 mL (3 x 1 = 3)
Household & Apothecary measures
 Grain
 Abbreviation: gr
 Metric equivalent: 60 mg
 1 gr = 60 mg
 How many milligrams in 3 gr?
 180 mg (3 x 60 = 180)
 (For grains see page 306 of your text book)
How many mL in 5 teaspoons?
A. 5 mL
B. 10 mL
C. 15 mL
D. 25 mL
E. None of the above
How many mL in 25 drops?
A. 25 mL
B. 50 mL
C. 75 mL
D. 100 mL
E. None of the above
The doctor says to give 2 oz, but you
only have a mL cup. How much do you
give in mL?
A. 2 mL
B. 15 mL
C. 30 mL
D. 60 mL
E. None of the above
How many milligrams in 3 grains?
A. 50 mg
B. 100 mg
C. 150 mg
D. 200 mg
E. None of the above
How many milliliters in 1
tablespoon?
A. 5 mL
B. 10 mL
C. 15 mL
D. 25 mL
E. None of the above
True / False: A 40% solution is
stronger than a 30% solution.
A. True
B. False
True / False: A 5% ointment is
stronger than a 2% ointment.
A. True
B. False
True / False: 100mL of a 3% solution
will contain 30 grams of drug.
A. True
B. False
2.8 mL of a 5.7% solution will contain
how many grams of drug? (Round to
the nearest tenth)
A.
B.
C.
D.
E.
2.8 g
5.7 g
0.1 g
0.2 g
None of the above