© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Chapter 5 Medical Math

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Importance of Math Frequently used in health care Requires 100 percent accuracy Errors can have dire consequences

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Math Anxiety Common problem Impedes performance Can be overcome False beliefs versus reality

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Question True or False: –If a person currently has problems with math, it can be assumed that it will always be a problem.

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Answer False Math anxiety –Learned behavior –Can be overcome

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Basic Calculations Whole numbers –Add –Subtract –Multiply –Divide

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Decimals Expressed in units of ten Placement values Zero used before decimal point if number begins to right of decimal point

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Working with Decimals Placement of decimal –Add –Subtract –Multiply –Divide

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Fractions Represents part of a whole Numerator Denominator

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Working with Fractions Add Subtract Multiply Divide Improper fractions Reducing fractions

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Percentages Expresses whole or part of a whole Whole expressed as 100 percent Convert to decimal –Then perform calculation

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Ratios Show relationships between numbers or like values Compare presence of one value to another Frequently used to express strength of solution

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Converting Decimals, Fractions, and Percentages Decimal to fraction Decimal to percentage Fraction to decimal Fraction to percentage

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Converting Decimals, Fractions, and Percentages Percentage to decimal Percentage to fraction Percentage to ratio Ratio to percentage

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Question True or False: –¾, 75%, and 0.75 are all equivalent.

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Answer True ¾ –Fraction –If converted to percentage = 75% –If converted to decimal = 0.75

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Rounding Numbers What does it mean? –Round up –Round down

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Question What is rounded to the nearest tenth? A.2 B.2.3 C.2.35

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Answer B rounded to nearest tenth = rounded to nearest whole number = rounded to nearest hundredth = 2.35

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Solving with Proportions Statement of equality between two ratios Used for converting from one unit to another Steps for solving problems

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Estimating Anticipate results Determine if answer is reasonable Calculate approximate answer

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. 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

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. 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)

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Military Time 24-hour clock No AM or PM Avoids errors 12 th hour = noon 24 th hour = midnight

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Question True or False: –The military time of 1600 is the same as 6 p.m. traditional time.

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Answer False 1600 = 4 p.m. 6 p.m. would be 1800 military time

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Military Clock

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Roman Numerals Arabic versus Roman numerals All numbers from seven key numerals –I, V, X, L, C, D, and M

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Roman Numerals Rules If smaller numeral is in front of larger numeral If smaller numeral is after larger numeral If same numeral is repeated Limit to number of times numeral is placed next to itself

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Question How would 43 be written in Roman numerals? A.XLIII B.XXXXIII C.XXXI

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Answer A. XLIII XLIII = 43 XXXXIII incorrect –Same numeral cannot be placed next to itself more than three times XXXI = 31

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Angles Comparison to reference plane Using angles in health care Measured in units –Degrees

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Angles

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Systems of Measurement Three systems –Distance Length –Capacity Volume –Mass Weight

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Systems of Measurement Nomenclature –Method of naming Need to convert between systems

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Household System Used in U.S. Nomenclature for distance/length Nomenclature for capacity/volume Nomenclature for mass/weight Common equivalents How to convert

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Question Which of the following is a capacity/volume unit in the household system? A.Inch B.Pound C.Ounce

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Answer C. Ounce Ounce –Unit of measurement for capacity/volume in household system –Also unit of measurement for mass/weight

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Answer C. Ounce Inch –Measurement for distance/length Pound –Measurement for mass/weight

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Metric System Used in Europe More accurate Easier to use Based on unit of ten Convert units by moving decimal Common prefixes

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Metric System Nomenclature for distance/length Nomenclature for capacity/volume Nomenclature for mass/weight

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Question How many centimeters are there in one meter? A.10 B.100 C.1000

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Answer B. 100 Meter –Base unit for distance/length in metric system –Centi = 1/100 –1 meter = 100 centimeters

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. 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

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Converting Systems Why converting between systems is needed in health care Common equivalencies between systems Equivalencies frequently not exact Steps to convert

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Question A patient reports that they drank 8 ounces (oz) of water. What is this in milliliters (mL)? A.80 mL B.120 mL C.240 mL

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Answer C. 240 mL 1 oz = 30 mL –8 oz = 240 mL

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. 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

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Temperature Scales

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Question True or False: –37 degrees C is a normal reading.

© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Answer True 37 degrees C = 98.6 degrees F –Normal reading