DOSAGE CALCULATIONS MADE
EASY
SOLVING PROBLEMS USING
DIMENSIONAL ANALYSIS
8TH EDITION
• AUTHOR(S)GLORIA PEARL
CRAIG
TEST BANK
,Question 1
A healthcare provider orders 0.5 g of a medication PO. The
medication is available as 250 mg tablets. How many tablets will
the nurse administer?
A. 0.5 tablets
B. 1 tablet
C. 2 tablets
D. 4 tablets
Correct Answer:
C. 2 tablets
Rationale:
Step 1: Identify the known values and the goal. The goal is to
find the number of tablets to administer. We know the desired
dose is 0.5 g and the available form is 250 mg/tablet.
Step 2: Set up the dimensional analysis equation to cancel units
and arrive at tablets.
(0.5 g) x (1000 mg / 1 g) x (1 tablet / 250 mg) = ? tablets
Step 3: Cancel the units (g and mg) and perform the calculation.
(0.5 x 1000 x 1) / 250 tablets = tablets = 2 tablets
Medication Safety Note:
Always verify that the medication order and the available
supply are in the same unit of measurement. Failure to convert
,grams to milligrams is a common source of medication errors,
potentially leading to a tenfold overdose.
Question 2
The nurse is preparing to administer 25 mg of a liquid
medication. The bottle contains 50 mg per 10 mL. How many
mL should the nurse administer?
A. 2 mL
B. 5 mL
C. 10 mL
D. 25 mL
Correct Answer:
B. 5 mL
Rationale:
Step 1: Identify the desired dose (25 mg) and the available
concentration (50 mg / 10 mL).
Step 2: Set up the dimensional analysis equation.
(25 mg) x (10 mL / 50 mg) = ? mL
Step 3: Cancel the units (mg) and calculate.
(25 x 10) / 50 mL = mL = 5 mL
Medication Safety Note:
When measuring liquid medications, use the appropriate
measuring device, such as an oral syringe or a medicine cup,
and read the measurement at eye level to ensure accuracy.
, Question 3
A patient is prescribed 0.125 mg of digoxin PO. The pharmacy
provides digoxin in a liquid concentration of 0.05 mg/mL. How
many mL will the nurse administer?
A. 0.25 mL
B. 1.25 mL
C. 2.5 mL
D. 25 mL
Correct Answer:
C. 2.5 mL
Rationale:
Step 1: Identify the desired dose (0.125 mg) and the available
concentration (0.05 mg/mL).
Step 2: Set up the dimensional analysis equation.
(0.125 mg) x (1 mL / 0.05 mg) = ? mL
Step 3: Cancel the units (mg) and calculate.
(0.125 x 1) / 0.05 mL = 0..05 mL = 2.5 mL
Medication Safety Note:
Digoxin has a narrow therapeutic index. Precise calculation and
administration are crucial. Always double-check calculations
with another licensed nurse if required by facility policy.
EASY
SOLVING PROBLEMS USING
DIMENSIONAL ANALYSIS
8TH EDITION
• AUTHOR(S)GLORIA PEARL
CRAIG
TEST BANK
,Question 1
A healthcare provider orders 0.5 g of a medication PO. The
medication is available as 250 mg tablets. How many tablets will
the nurse administer?
A. 0.5 tablets
B. 1 tablet
C. 2 tablets
D. 4 tablets
Correct Answer:
C. 2 tablets
Rationale:
Step 1: Identify the known values and the goal. The goal is to
find the number of tablets to administer. We know the desired
dose is 0.5 g and the available form is 250 mg/tablet.
Step 2: Set up the dimensional analysis equation to cancel units
and arrive at tablets.
(0.5 g) x (1000 mg / 1 g) x (1 tablet / 250 mg) = ? tablets
Step 3: Cancel the units (g and mg) and perform the calculation.
(0.5 x 1000 x 1) / 250 tablets = tablets = 2 tablets
Medication Safety Note:
Always verify that the medication order and the available
supply are in the same unit of measurement. Failure to convert
,grams to milligrams is a common source of medication errors,
potentially leading to a tenfold overdose.
Question 2
The nurse is preparing to administer 25 mg of a liquid
medication. The bottle contains 50 mg per 10 mL. How many
mL should the nurse administer?
A. 2 mL
B. 5 mL
C. 10 mL
D. 25 mL
Correct Answer:
B. 5 mL
Rationale:
Step 1: Identify the desired dose (25 mg) and the available
concentration (50 mg / 10 mL).
Step 2: Set up the dimensional analysis equation.
(25 mg) x (10 mL / 50 mg) = ? mL
Step 3: Cancel the units (mg) and calculate.
(25 x 10) / 50 mL = mL = 5 mL
Medication Safety Note:
When measuring liquid medications, use the appropriate
measuring device, such as an oral syringe or a medicine cup,
and read the measurement at eye level to ensure accuracy.
, Question 3
A patient is prescribed 0.125 mg of digoxin PO. The pharmacy
provides digoxin in a liquid concentration of 0.05 mg/mL. How
many mL will the nurse administer?
A. 0.25 mL
B. 1.25 mL
C. 2.5 mL
D. 25 mL
Correct Answer:
C. 2.5 mL
Rationale:
Step 1: Identify the desired dose (0.125 mg) and the available
concentration (0.05 mg/mL).
Step 2: Set up the dimensional analysis equation.
(0.125 mg) x (1 mL / 0.05 mg) = ? mL
Step 3: Cancel the units (mg) and calculate.
(0.125 x 1) / 0.05 mL = 0..05 mL = 2.5 mL
Medication Safety Note:
Digoxin has a narrow therapeutic index. Precise calculation and
administration are crucial. Always double-check calculations
with another licensed nurse if required by facility policy.
