Pharmacy Calculations Exam ACTUAL
QUESTIONS AND CORRECT ANSWERS
Dose - CORRECT ANSWER • The amount of medication to be administered to a
patient.
• May be measured in milligrams (mg), milliliters (mL), units, or milliequivalents (mEq).
How to convert a decimal to percent - CORRECT ANSWER To convert a decimal to
percent:
1. Multiply the number by 100.
2. Add a percent (%) sign.
Examples:
• 0.45 * 100 = 45%
• 1.00 * 100 = 100%
• 1.25 * 100 = 125%
How to convert a percent to decimal - CORRECT ANSWER To convert a percent to
decimal:
1. Remove the % sign.
2. Divide by 100.
Examples:
• 95% / 100 = 0.95
• 50% / 100 = 0.50
• 0.25% / 100 = .0025
• 105% / 100 = 1.05
How to convert a percent to a fraction - CORRECT ANSWER 1• Drop the % sign.
2• Write the value of the number as the numerator.
,3• Place number over a denominator of 100.
4• Reduce the fraction to its lowest terms.
Example: 75%
= --> (both divisible by 25)
=3/4
Percentages and medication strength - CORRECT ANSWER • Percent means "parts
per 100".
• Can calculate using ratios, fractions, or decimals.
How to convert a fraction to a ratio - CORRECT ANSWER • Place the numerator first.
• Followed by a colon.
• Place the denominator next.
Example:
• 1/2 is "1 over 2"
• 1 : 2 is "1 to 2"
Calculate percent by setting up a proportion - CORRECT ANSWER Parts of the whole
÷ Whole = Percent (%) ÷ 100
To solve:
1. Two of the three variables need to be present: parts of the whole, the whole, or the percent.
2. Identify each term as part of the whole, the whole, or a percent.
3. Place values in the equation.
4. Cross multiply across the equal sign.
5. Divide to find the missing term.
,How to convert a ratio to a percent - CORRECT ANSWER 1• Divide the first number
by the second number.
2• Multiply by 100.
3• Add the % sign.
Example:
• 1 : 10
= 1/10 = 0.10
= 0.10 * 100
= 10
= 10%
How to calculate the number of doses in a prescription (Option 1) - CORRECT
ANSWER Dose to be given = [ DD (Desired dose) / DH (dose on hand) ] * QTY
(quantity)
Example: How many 1 tsp doses are in a 4 oz. bottle of Prozac Liquid Solution 20 mg/5mL?
Given: 120 mL = 4 oz.
1 oz = 30 mL
1 tsp = 5 mL
1. Convert oz. to mL
• 1 oz. / 30 mL = 4 oz. / X mL
• 1 * X = 30 * 4
• X = 120 mL
2. Solve for the number of doses
• 1 dose / 5 mL = X doses / 120 mL
• 5 * X = 1 * 120
, • 5X = 120
• X =
• X = 24 doses
There are 24 doses (of 5 mL each) in a 4 oz. (120 mL) bottle.
How to calculate the number of doses in a prescription (Example Option 2 - dimensional
analysis) - CORRECT ANSWER How many 1 tsp doses are in a 4 oz. bottle Prozac
Liquid Solution 20 mg/5mL?
Given:
120 mL = 4 oz.
1 oz = 30 mL
1 tsp = 5 mL
X = 4 oz * (30 ml / 1 oz.) * (1 tsp / 5 ml)
X = (4 * 30 tsp) / 5
X = 120 tsp / 5
X = 24 tsp
24 tsp are in a 4 oz. bottle
Dosage amount to calculate doses - CORRECT ANSWER Always use the higher
dosage amount when performing dosage calculations on prescriptions that have a range for
the dose.
Rx (Prescription): "Ibupropfen 400 mg
i - ii po q 6hr prn pain
Disp. #120"
QUESTIONS AND CORRECT ANSWERS
Dose - CORRECT ANSWER • The amount of medication to be administered to a
patient.
• May be measured in milligrams (mg), milliliters (mL), units, or milliequivalents (mEq).
How to convert a decimal to percent - CORRECT ANSWER To convert a decimal to
percent:
1. Multiply the number by 100.
2. Add a percent (%) sign.
Examples:
• 0.45 * 100 = 45%
• 1.00 * 100 = 100%
• 1.25 * 100 = 125%
How to convert a percent to decimal - CORRECT ANSWER To convert a percent to
decimal:
1. Remove the % sign.
2. Divide by 100.
Examples:
• 95% / 100 = 0.95
• 50% / 100 = 0.50
• 0.25% / 100 = .0025
• 105% / 100 = 1.05
How to convert a percent to a fraction - CORRECT ANSWER 1• Drop the % sign.
2• Write the value of the number as the numerator.
,3• Place number over a denominator of 100.
4• Reduce the fraction to its lowest terms.
Example: 75%
= --> (both divisible by 25)
=3/4
Percentages and medication strength - CORRECT ANSWER • Percent means "parts
per 100".
• Can calculate using ratios, fractions, or decimals.
How to convert a fraction to a ratio - CORRECT ANSWER • Place the numerator first.
• Followed by a colon.
• Place the denominator next.
Example:
• 1/2 is "1 over 2"
• 1 : 2 is "1 to 2"
Calculate percent by setting up a proportion - CORRECT ANSWER Parts of the whole
÷ Whole = Percent (%) ÷ 100
To solve:
1. Two of the three variables need to be present: parts of the whole, the whole, or the percent.
2. Identify each term as part of the whole, the whole, or a percent.
3. Place values in the equation.
4. Cross multiply across the equal sign.
5. Divide to find the missing term.
,How to convert a ratio to a percent - CORRECT ANSWER 1• Divide the first number
by the second number.
2• Multiply by 100.
3• Add the % sign.
Example:
• 1 : 10
= 1/10 = 0.10
= 0.10 * 100
= 10
= 10%
How to calculate the number of doses in a prescription (Option 1) - CORRECT
ANSWER Dose to be given = [ DD (Desired dose) / DH (dose on hand) ] * QTY
(quantity)
Example: How many 1 tsp doses are in a 4 oz. bottle of Prozac Liquid Solution 20 mg/5mL?
Given: 120 mL = 4 oz.
1 oz = 30 mL
1 tsp = 5 mL
1. Convert oz. to mL
• 1 oz. / 30 mL = 4 oz. / X mL
• 1 * X = 30 * 4
• X = 120 mL
2. Solve for the number of doses
• 1 dose / 5 mL = X doses / 120 mL
• 5 * X = 1 * 120
, • 5X = 120
• X =
• X = 24 doses
There are 24 doses (of 5 mL each) in a 4 oz. (120 mL) bottle.
How to calculate the number of doses in a prescription (Example Option 2 - dimensional
analysis) - CORRECT ANSWER How many 1 tsp doses are in a 4 oz. bottle Prozac
Liquid Solution 20 mg/5mL?
Given:
120 mL = 4 oz.
1 oz = 30 mL
1 tsp = 5 mL
X = 4 oz * (30 ml / 1 oz.) * (1 tsp / 5 ml)
X = (4 * 30 tsp) / 5
X = 120 tsp / 5
X = 24 tsp
24 tsp are in a 4 oz. bottle
Dosage amount to calculate doses - CORRECT ANSWER Always use the higher
dosage amount when performing dosage calculations on prescriptions that have a range for
the dose.
Rx (Prescription): "Ibupropfen 400 mg
i - ii po q 6hr prn pain
Disp. #120"
