HOSA Medical Math Guidelines (August 2020) Page 1 of 4
Medical Math
Event Summary
Medical Math provides members with the opportunity to gain knowledge and skills required to
identify, solve, and apply mathematical principles. This competitive event consists of a written
test with tie-breaker questions. This event aims to inspire members to learn about the
integration of mathematics in health care, including temperature, weights, and measures used
in the health community.
Dress Code Competitors must be in official HOSA uniform or in proper business attire. Bonus points will
be awarded for proper dress.
General Rules 1. Competitors in this event must be active members of HOSA-Future Health
Professionals and in good standing.
2. Secondary and Postsecondary/Collegiate divisions are eligible to compete in this
event.
3. Competitors must be familiar with and adhere to the “General Rules and Regulations of
the HOSA Competitive Events Program (GRR)."
4. All competitors shall report to the site of the event at the time designated for each
round of competition. At ILC, competitor’s photo ID must be presented prior to ALL
competition rounds.
Official References
• Simmers, L., Simmers-Nartker, Simmers-Kobelak. DHO: Health Science.
Cengage Learning, Latest edition.
• Olsen, et al, Medical Dosage Calculations. Pearson Latest edition.
• Craig, Gloria P., Clinical Calculations Made Easy. Wolters Kluwer, Latest edition.
• Helms, Joel R., Mathematics for Health Sciences: A Comprehensive Approach.
Cengage Learning. Latest edition.
Written Test
5. Test Instructions: The written test will consist of 50 multiple choice items in a
maximum of 90 minutes.
6. Time Remaining Announcements: There will be a verbal announcement when
there are 60 minutes, 30 minutes, 15 minutes, 5 minutes, and 1 minute remaining to
complete the test.
7. A series of ten (10) complex, multi-step tie breaking questions will be administered
with the original test. In case of a tie, successive tie-breaker questions will be used
until a winner is determined. In the tie-breaker, correct spelling is required for an
item to be considered correct.
New for 2020-2021
Competitor orientation deleted from ILC.
HOSA Medical Math Guidelines (August 2020) Page 2 of 4
8. Test Plan:
Mathematical essentials .................................................................. 5%
Measurement and conversion problems ....................................... 20%
Drug dosages and intravenous solutions ...................................... 35%
Dilutions, solutions and concentrations ......................................... 25%
Interpreting medical information .................................................... 15%
o Charts, graphs, tables
o Basic statistics: mean, median, mode, standard deviation
o Calculating body surface
NOTE: 1. Abbreviations will be used in the written problems. In addition, the test
will use standard medical abbreviations as designated in the Simmers
DHO Health Science reference.
2. At least half of the computation and calculation problems will involve
conversions.
9. At the International Leadership Conference, HOSA will provide basic
handheld calculators (no graphing calculators) for addition, subtraction, division,
multiplication and square root. Check with State Advisor to determine if a calculator
will be used at the State level.
10. All competitors will receive two (2) 8.5x11” sheets of blank paper for use during the
test.
11. The medical math “Reference Materials Summary” included in these guidelines
(page 4) will be used as the official reference for the test for uniformity.
Competitors may NOT use this summary page or any type of conversion chart
or resource during the test.
12. When a Scantron form is used – the Scantron form for this event will require
competitors to grid-in their responses.
At the state-level, when a paper/pencil test is used or the test is administered on a
computer, the competitor will write in or key in his/her response to each question.
13. Converting between measurement systems will often render a different answer
depending upon which systems and conversions are being used. The answer to a
calculation problem will ultimately be the same answer after appropriate rounding.
ROUNDING: When rounding decimal numbers to the nearest tenths, hundredths, or
thousandths, look to the immediate right of the digit located in the position to be
rounded. If the number to the direct right is 5 or larger, round to the position up one
number and drop everything that follows. If the number to the direct right is 4 or
smaller, leave the position being rounded as is and drop everything that follows.
In specific situations, answers will be rounded per medical protocol. For example,
pediatric dosage is always rounded DOWN to avoid potential overdose. Unless
otherwise indicated, all answers should be rounded to the nearest whole
number. (Examples: 31.249 (rounded down) = 31 and 23.75 (rounded up) = 24).
HOSA Medical Math Guidelines (August 2020) Page 3 of 4
14. Sample Test Questions
*Competitors will grid-in (or write in) their answers to the test problems.
1. An IV bag of 500 mL solution is started at 1900. The flow rate is 38 gtts per minute,
and the drop factor is 10 gtts per mL. At what time (24-hour clock) will this infusion
finish?
(Craig pp 174-178)
Solution 38 gtts/1 min x 1 mL/10 gtts = 3.8 mL/min
3.8 mL/1 min x 60 min/1 hr = 228 mL/hr
500 mL x 1 hr/228 mL = 2.19 hr
0.19 hr x 60 min/1 hr = 11.4 minutes
1900 hr + 2 hrs 11 min = 2111 hours
2. A patient with an eating disorder weighs 95½ lbs. What is the patient’s weight in kg?
Round to the nearest tenth.
(Helms pp 110-114)
Solution 95.5 lb x 1 kg/2.2 lbs = 43.40909 kg Rounded = 43.4 kg
3. How many grams of sodium chloride are needed to prepare 500 mL of a 5% solution?
(Olson pp214-227)
Solution 5% = 5 g/100 mL = 0.05 g/1 mL
0.05 g/1 mL x 500 mL = 25 g
Final Scoring
15. Final rank is determined by the test score. In case of a tie, the tie-breaking questions
will be used to determine the rank.
Competitor Must Provide:
Two #2 lead pencils with eraser
Photo ID
HOSA Medical Math Guidelines (August 2020) Page 4 of 4
Medical Math – SS/PSC
Reference Materials Summary
METRIC EQUIVALENTS
Length
Temperature
1 meter (m) = 100 centimeters (cm) = 1000 millimeters (mm)
1 centimeters (cm) = 10 millimeters (mm)
oC (Degrees Celsius) = (oF - 32) 5/9
oF (Degrees Fahrenheit) = (oC) 9/5 + 32
Weight
Weight Conversion
1 kilogram (kg) = 1000 grams (g)
1 kilogram (kg) = 2.2 pounds (lb)
1 gram (g) = 1000 milligrams (mg)
1 pound (lb) = 16 ounces (oz)
1 milligram (mg) = 1000 micrograms (mcg)
Volume for Solids
Volume for Fluids
1000 cubic decimeters (dm) = 1 cubic meter (m3)
1 liter (L) = 1000 milliliters (mL)
1000 cubic centimeters (cm3) = 1 cubic decimeter (dm3)
10 centiliters (cL) = 1 deciliter (dL)
1000 cubic millimeters (mm3)= 1 cubic centimeter (cm3 or cc)
10 deciliters (dL) = 1 liter (L)
1 cubic centimeters (cm3 or cc) = 1 milliliter (mL)
Units (U) = a measure for drugs such as insulin
APPROXIMATE EQUIVALENTS AMONG SYSTEMS
Metric
240 milliliters (mL)
30 milliliters (mL)
15 milliliters (mL)
5 milliliters (mL)
1 milliliter (mL)
0.0667 milliliters (mL)
1 meter (m)
2.54 centimeters (cm)
Formulas
Standard Deviation Formula
for Sample Data
Body Surface Area
BSA (m2) = √([height (cm) x weight(kg)]/3,600)
BSA (m2) = √([height (in) x weight(lb)]/3,131)
References
Craig, Gloria. Clinical Calculations Made Easy. Lippincott, Williams & Wilkins, Latest Edition. 6e.
Helms, Joel R., Mathematics for Health Sciences: A Systematic Approach. Cengage Learning. Latest edition.
Olsen, et al, Medical Dosage Calculations. Prentice Hall. Latest edition. 11e.