1. Chapter 5 Medical Math

2. Importance of Math Frequently used in health care Requires 100% accuracy Errors can have dire consequences

3. Math Anxiety Common problem Impedes performance Can be overcome False beliefs versus reality

4. Question True or False: –If a person currently has problems with math, it can be assumed that it will always be a problem.

5. Answer False Math anxiety –Learned behavior –Can be overcome

6. Basic Calculations Whole numbers –Add –Subtract –Multiply –Divide

7. Decimals Expressed in units of ten Placement values Zero used before decimal point if number begins to right of decimal point

8. Decimal Placement Values

9. Working with Decimals Placement of decimal –Add –Subtract –Multiply –Divide

10. Fractions Represents part of a whole Numerator Denominator

11. Fraction – Comparison of Parts

12. Working with Fractions Add Subtract Multiply Divide Improper fractions Reducing fractions

13. Percentages Expresses whole or part of a whole Whole expressed as 100% (percent) Convert to decimal –Then perform calculation

14. Ratios Show relationships between numbers or like values Compare presence of one value to another Frequently used to express strength of solution

15. Converting Decimals, Fractions, and Percentages Decimal to fraction Decimal to percentage Fraction to decimal Fraction to percentage

16. Converting Decimals, Fractions, and Percentages Percentage to decimal Percentage to fraction Percentage to ratio Ratio to percentage

17. Question True or False: –¾, 75%, and 0.75 are all equivalent.

18. Answer True ¾ –Fraction –If converted to percentage = 75% –If converted to decimal = 0.75

19. Rounding Numbers What does it mean? –Round up –Round down

20. Question What is 2.346 rounded to the nearest tenth? A.2 B.2.3 C.2.35

21. Answer B. 2.3 2.346 rounded to nearest tenth = 2.3 2.346 rounded to nearest whole number = 2 2.346 rounded to nearest hundredth = 2.35

22. Solving with Proportions Statement of equality between two ratios Used for converting from one unit to another Steps for solving problems

23. Estimating Anticipate results Determine if answer is reasonable Calculate approximate answer Helps prevent errors

24. Question If the order is to give 2 grams of a medication and you have 1,000 milligram tablets, how many tablets would you give? A.½ tablet B.2 tablets C.4 tablets

25. Answer B. 2 tablets 1 gram = 1,000 milligrams –2 grams = 2,000 milligrams or 2 tablets ½ tablet = 500 milligrams –0.5 grams (too little) 4 tablets = 4,000 milligrams –4 grams (too much)

26. Military Time 24-hour clock No a.m. or p.m. Avoids errors 12 th hour = noon 24 th hour = midnight

27. Question True or False: –The military time of 1600 is the same as 6 p.m. traditional time.

28. Answer False 1600 = 4 p.m. 6 p.m. would be 1800 military time

29. Military Clock

30. Roman Numerals Arabic versus Roman numerals All numbers from seven key numerals –I, V, X, L, C, D, and M

31. Roman Numerals Rules If smaller numeral is in front of larger numeral, it is subtracted If smaller numeral is after larger numeral, it is added If same numeral is repeated, they are added Limit to three the number of times numeral is placed next to itself

32. Question How would 43 be written in Roman numerals? A.XLIII B.XXXXIII C.XXXI

33. Answer A. XLIII XLIII = 43 XXXXIII incorrect –Same numeral cannot be placed next to itself more than three times XXXI = 31

34. Angles Comparison to reference plane Using angles in health care Measured in units –Degrees

35. Angles

36. Systems of Measurement Three systems –Distance Length –Capacity Volume –Mass Weight

37. Systems of Measurement Nomenclature –Method of naming Need to convert between systems

38. Household System Used in U.S. Nomenclature for distance/length Nomenclature for capacity/volume Nomenclature for mass/weight Common equivalents How to convert

39. Question Which of the following is a capacity/volume unit in the household system? A.Inch B.Pound C.Ounce

40. Answer C. Ounce –Also measurement of mass/weight Inch = measurement of distance/length Pound = measurement of mass/weight

41. Metric System Used in Europe More accurate Easier to use Based on unit of ten Convert units by moving decimal Common prefixes

42. Metric System Nomenclature for distance/length Nomenclature for capacity/volume Nomenclature for mass/weight

43. Question How many centimeters are there in one meter? A.10 B.100 C.1000

44. Answer B. 100 Meter –Base unit for distance/length in metric system –Centi = 1/100 –1 meter = 100 centimeters

45. Apothecary System Oldest and least used Nomenclature for capacity/volume Nomenclature for mass/weight Common equivalents How to convert Roman numerals and abbreviation for half

46. Converting Systems Why converting between systems is needed in health care Common equivalencies between systems Equivalencies frequently not exact Steps to convert

47. Question A patient reports drinking 8 ounces (oz) of water. What is this in milliliters (mL)? A.80 mL B.120 mL C.240 mL

48. Answer C. 240 mL 1 oz = 30 mL –8 oz = 240 mL

49. Medication Safety Characters that cause over 50% of error misidentifications: l/1 O/0 Z/2 1/7

50. Temperature Conversion Fahrenheit (F) used in U.S. Celsius (C) used in Europe Boiling point and freezing point comparisons Converting between Celsius and Fahrenheit readings

51. Temperature Scales

52. Question True or False: 37 degrees C is a normal reading.

53. Answer True 37 degrees C = 98.6 degrees F –Normal reading