DOSAGE CALCULATIONS MADE
EASY
SOLVING PROBLEMS USING
DIMENSIONAL ANALYSIS
8TH EDITION
• AUTHOR(S)GLORIA PEARL
CRAIG
TEST BANK
,Question 1 (Easy)
The nurse is preparing to administer a medication to a patient.
The order reads: "Acetaminophen 650 mg PO every 6 hours
PRN for pain." The pharmacy provides acetaminophen tablets in
a 325 mg strength. How many tablets should the nurse
administer?
A. 0.5 tablets
B. 1 tablet
C. 1.5 tablets
D. 2 tablets
Correct Answer: D. 2 tablets
Rationale:
• Step 1: Identify the Goal. The goal is to find the number of
tablets to give, which is "tablets."
• Step 2: Set up Dimensional Analysis.
Desired Dose / Dose on Hand * Quantity
(650 mg) / (325 mg/tablet) * 1 tablet
• Step 3: Calculate.
= tablets = 2 tablets
• Medication Safety Note: Always verify that the medication
order and the available medication are the same form
(e.g., both for PO administration) and check the patient's
identification and allergies before administration.
,Question 2 (Easy)
A provider orders cephalexin 500 mg PO every 12 hours for a
patient with a skin infection. The available medication is
cephalexin 250 mg/5 mL. How many milliliters will the nurse
administer per dose?
A. 2 mL
B. 5 mL
C. 10 mL
D. 15 mL
Correct Answer: C. 10 mL
Rationale:
• Step 1: Identify the Goal. The goal is to find the volume in
mL to administer.
• Step 2: Set up Dimensional Analysis.
(500 mg) / (250 mg / 5 mL) * 5 mL
• Step 3: Calculate.
= (500 mg / 250 mg) * 5 mL = 2 * 5 mL = 10 mL
• Medication Safety Note: Use an appropriate measuring
device, such as an oral syringe or medication cup, to
ensure an accurate measurement, and double-check the
calculation with another nurse if policy dictates.
, Question 3 (Easy)
The nurse needs to administer 1.5 g of a medication. The
pharmacy sends the medication in 500 mg tablets. How many
tablets should the nurse give?
A. 1.5 tablets
B. 3 tablets
C. 4 tablets
D. 2.5 tablets
Correct Answer: B. 3 tablets
Rationale:
• Step 1: Identify the Goal. The goal is to find the number of
tablets.
• Step 2: Set up Dimensional Analysis. First, convert grams
to milligrams. 1 g = 1000 mg.
(1.5 g) * (1000 mg / 1 g) * (1 tablet / 500 mg)
• Step 3: Calculate.
= 1.5 * tablets = tablets = 3 tablets
• Medication Safety Note: Always perform conversions
carefully, remembering that 1 g is equal to 1000 mg.
Confusing grams and milligrams is a common and
dangerous calculation error.
EASY
SOLVING PROBLEMS USING
DIMENSIONAL ANALYSIS
8TH EDITION
• AUTHOR(S)GLORIA PEARL
CRAIG
TEST BANK
,Question 1 (Easy)
The nurse is preparing to administer a medication to a patient.
The order reads: "Acetaminophen 650 mg PO every 6 hours
PRN for pain." The pharmacy provides acetaminophen tablets in
a 325 mg strength. How many tablets should the nurse
administer?
A. 0.5 tablets
B. 1 tablet
C. 1.5 tablets
D. 2 tablets
Correct Answer: D. 2 tablets
Rationale:
• Step 1: Identify the Goal. The goal is to find the number of
tablets to give, which is "tablets."
• Step 2: Set up Dimensional Analysis.
Desired Dose / Dose on Hand * Quantity
(650 mg) / (325 mg/tablet) * 1 tablet
• Step 3: Calculate.
= tablets = 2 tablets
• Medication Safety Note: Always verify that the medication
order and the available medication are the same form
(e.g., both for PO administration) and check the patient's
identification and allergies before administration.
,Question 2 (Easy)
A provider orders cephalexin 500 mg PO every 12 hours for a
patient with a skin infection. The available medication is
cephalexin 250 mg/5 mL. How many milliliters will the nurse
administer per dose?
A. 2 mL
B. 5 mL
C. 10 mL
D. 15 mL
Correct Answer: C. 10 mL
Rationale:
• Step 1: Identify the Goal. The goal is to find the volume in
mL to administer.
• Step 2: Set up Dimensional Analysis.
(500 mg) / (250 mg / 5 mL) * 5 mL
• Step 3: Calculate.
= (500 mg / 250 mg) * 5 mL = 2 * 5 mL = 10 mL
• Medication Safety Note: Use an appropriate measuring
device, such as an oral syringe or medication cup, to
ensure an accurate measurement, and double-check the
calculation with another nurse if policy dictates.
, Question 3 (Easy)
The nurse needs to administer 1.5 g of a medication. The
pharmacy sends the medication in 500 mg tablets. How many
tablets should the nurse give?
A. 1.5 tablets
B. 3 tablets
C. 4 tablets
D. 2.5 tablets
Correct Answer: B. 3 tablets
Rationale:
• Step 1: Identify the Goal. The goal is to find the number of
tablets.
• Step 2: Set up Dimensional Analysis. First, convert grams
to milligrams. 1 g = 1000 mg.
(1.5 g) * (1000 mg / 1 g) * (1 tablet / 500 mg)
• Step 3: Calculate.
= 1.5 * tablets = tablets = 3 tablets
• Medication Safety Note: Always perform conversions
carefully, remembering that 1 g is equal to 1000 mg.
Confusing grams and milligrams is a common and
dangerous calculation error.
