Medical Math for Healthcare Professionals

Medical Math  All health care workers are required to perform simple math calculations when doing various tasks.  Knowing basic math calculations are essential for all health care professionals to be successful.

Numbers  Numbers are expressed in different forms: –Whole numbers: are the counting numbers and zero; they do not contain decimals or fractions –Nonwhole numbers: are numbers that have decimals ex: –Mixed numbers: are whole numbers and a fraction ex: 12 ½ –Percetages: the whole or all of something ex: 12%

Numbers  Numbers that have more than one digit are defined by their place value. For ex: –The number 7777  Place value –7 (thousands) –7 (hundreds) –7 (tens) –7 (ones) *This number is described by saying “seven thousand, seven hundred seventy-seven” *Numbers are written with a comma placed to the left of every third digit. 7,777

Numbers  Numbers indicating less than a whole number are placed to the right of a decimal. –The number 7, is given the following place values  Place value –7, (thousands) –7 (hundreds) –7 (tens) –7. (ones) –2 (tenths) –5 (hundredths) –5 (thousandths) *It is written 7, and described as “seven thousand, seven hundred seventy-seven and two hundred and fifty-five thousandths”

Numbers  Additions- the totaling of two or more numbers  Subtraction- the opposite of addition; taking a number away from another number  Multiplication- a quick easy way to add; finding the product of two numbers  Division- the opposite of multiplication; the process of separating into parts

The Metric System  The health care worker is expected to measure and calculate weights, heights, and volume in metric units of measure.  Understanding how to convert standard and metric units of measure is helpful in various settings settings

Metric System  The health care industry uses the metric system for measuring. It is used by 90% of the world and is known as the International System of Units.

4 Basic Rules of Metric System 1. Numbers indicating less than one unit are always written in a decimal form, not as fractions. Ex: 1/10=0.1 or 1/100=0.01 or 1/1000= When writing decimals, if there is no number before the decimal, always write a 0. Ex:.1 is 0.1 or.5 is Abbreviations for metric terms are never plural; they are always written in singular form. Ex: grams is g, not gs; liters is L, not Ls. Always capitalize the abbreviation for L for liter to reduce confusing the lowercase l with the Leave a space between the number and the abbreviation, as shown in the following ex: 8 g or 0.1 dm.

Metric Terms and Abbreviations TermAbbreviationsMeasures In Place of Metermlength Inch, foot, yard, mile gramgweight Ounce, pound literLvolume Fluid ounce, cup, pint, quart, gallon

Metric Terms and Abbreviations TermAbbreviations What is Measures kilok 1,000 units hectoh 100 units

Metric Terms and Abbreviations TermAbbreviation What is Measures decid 1/10 or 0.1 unit centic 1/100 or 0.01 unit millim 1/1000 or unit

Using the Metric System to Measure  A meter stick can be used to measure length in the following units: –Centimeter (cm) –Millimeter (mm) –Meters (m) *1 meter is slightly more than 3 ft

Measurements  Measures of Length –1 hectogram= 100 meters –1.5 hectogram= 150 meters –1 kilometer= 1,000 meters –1.5 kilometer= 1,500 meteres  Measures of Weight –1 hectogram= 100 g –1.5 hectogram= 150 g –1 kilogram= 1,000 g –1.5 kilogram= 1,500 g

Using Metric System to Measure  Liters, Milliliters and Cubic Centimeters –A liter (L) is slightly larger than a quart –A milliliter (mL) is 1/1000 of a liter –Cubic Centimeter (CC) are interchangeable with mL –Scales can be used to measure weight in grams, hectograms, and kilograms –Celsius (C) and Centigrade- the metric measure of heat is Celsius or centigrade, which are the same.

Changing Ounces to Millimeters and Cubic Centimeters (cc) 1 oz medicine 1 oz x 30 cc/mL = 30 cc=30 mL 8 oz water 8 oz x 30 cc/mL = 240 cc= 240mL 6 oz soup 6 oz x 30 cc/mL = 180 cc = 180mL 4 oz juice 4 oz x 30 cc/mL = 120 cc = 120mL 12 oz soda 12 oz x 30 cc/mL = 360 cc = 360mL

Measuring Devices  Health care workers use various types of measuring devices to measure liquid.

Changing Pounds to Kilograms and Kilograms to Pounds  110 lb changed to kilograms: 110 lb x 0.45 kg/lb = 49.5 kg  200 lb changed to kg: 200 lb x 0.45 x kg/lb = 91 kg  50 kg changed to lb = 50 kg x 2.2 lb/kg = 110 lb  91 kg changed to lb = 91 kg x 2.2 lb/kg = 200 lb  To change lb to kg, multiply the number of lbs by 0.45 lb/kg  To change kg to lb, multiply the number of kg by 2.2 lb/kg

Changing Ounces to Grams Changing Ounces to Grams  One ounce (oz) = 30 grams (g).  To change ounces to grams, multiply 30 g/oz by the number of ounces.  To change grams to ounces, divide 30 g/oz into the number of grams  1 oz changed to grams: 1 oz x 30 g/oz = 30 g  8 oz changed to grams: 8 oz x 30 g/oz = 240 g

24 hour/Military Time Clock  Medical facilities frequently use the 24-hour clock system. The 24-hour clock system clearly states time and eliminates confusion on documentation.  Military time is always expressed in four digits and no colons are used to separate hours and minutes.  Always use a 0 to complete the four digit number ex: for 1:00am = 0100  Remember to state the time in hundreds ex: 1:00 am= 0100= zero one hundred hours; 1100= eleven hundred hours (11am) *Greenwich time- standard time; a 12-hour clock

Military- 24-hour clock