Unit 2 - Medical Math – Conversions
In order to work safely in health care, it is essential to be able to add, subtract,
multiply, and divide whole numbers, decimals, fractions, and percentages. An
understanding of equivalents when using decimals, fractions, and percentages is
also needed. Health care work sometimes requires that units from one system of
measurement be converted to those of another, as in converting between the
Fahrenheit and Celsius systems of temperature measurement, or converting
weight in pounds to weight in kilograms. Following are some common
conversions used in health care:
To convert temperature in Fahrenheit to Celsius or Celsius to Fahrenheit:
C = (F – 32) x 5/9
F = (C x 9/5) + 32
Some common conversions:
2.2 pounds = 1 kilogram
1 cup = 8 ounces (8 oz)
1 inch = 2.5 centimeters
1 ounce = 30 ml
1 teaspoon = 5ml
16 ounces = 1 pound (1 lb)
THE METRIC SYSTEM:
Distance/length: meter (m)
Capacity/volume: liter (l or L)
Mass/weight: gram (g or gm)
kilo = 1000
deci = .01
hecto = 100
centi = .001
deca = 10
milli = .0001
BASE = 1
*King Henry Died by drinking chocolate milk
Unit 2 Medical Math - Conversions
Examples:
1) A patient’s oral intake is being measured. For breakfast, he drank 240 ml of
coffee, 120 ml of juice, and 60 ml of water. What is his total intake?
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2) A patient is on a diet to lose weight. Last month she weighed 172lbs. This
month she weighs 159 lbs. How much weight did she lose?
____________________________
3) A physical therapist is buying elastic bandages. Each roll costs $3.25. How
much would 3 rolls cost?
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4) A central supply worker orders 12 new stethoscopes for a total cost of
$108.48. How much does each stethoscope cost?
____________________________
5) A surgical nurse works 1 ¼ hours in preoperative care, 2 ½ hours in the
operating room, and 3 ¾ hours in the recovery room. What is the total
number of hours worked?
____________________________
6) An electrocardiograph technician knows that one small block on ECG paper
represents 1/25 of a second. How many seconds are represented by 150
small blocks?
____________________________
7) A laboratory technician counts 7,742 leukocytes (white blood cells). If 36
percent of the leukocytes are lymphocytes, how many lymphocytes are
present?
____________________________
8) A doctor orders 500 mg of Sumycin for a patient. Sumycin is available in 250
mg capsules. How many capsules should be given to the patient?
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9) How many liters are in 2.5 kiloliters?
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10) A patient drinks 90 ml of water. How many ounces did the patient drink?
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