Conversion of Clinical Measurements of Numbers, Time, and Temperature

Chapter 3


Conversion of Clinical Measurements of Numbers, Time, and Temperature



Objectives



• Express Arabic numbers in Roman numerals


• Express Roman numerals in Arabic numbers


• Convert time between standard time and military (or universal) time


• Convert temperature between Fahrenheit and Celsius



Key Words








Pretest


Follow the directions below and show all of your calculations as appropriate. Remember that this is a pretest to judge your current knowledge of the materials presented in this chapter.


Change the following to Roman numerals.



Change the following to Arabic numbers.



Change the following to universal, or 24-hour, time.



Change the following to 12-hour time.



Change the following temperatures as indicated. Round to the nearest tenth.





Introduction


Whether in the hospital setting or in the community pharmacy, time, temperature, and the ability to read numbering systems are essential so the correct amount of medication will be given at the correct time and at the correct temperature if that is essential. A pharmacy technician will use both Arabic numerals, such as 1, 2, 3, and so on, and Roman numerals, such as I, V, X, and so on, when interpreting physicians’ orders. As citizens of the Western Hemisphere, we are familiar with Arabic numbers, which are used daily, and numbers that are related to the English system of measurement. These numbers are used for steps in our daily lives from writing a check to looking at a page number in a book. Numbers in the preface of a book, however, are usually written in Roman numerals.


Most of you probably have not used Roman numerals for many years, but these numerical symbols will be used daily in the medical field. In the same manner, in our daily world we use the standard clock whereas in patient settings we often use military time to prevent misinterpretation of the medicinal order. Finally, temperature is read and recorded in Fahrenheit in our daily lives, using 32° as the freezing point of water and 212° as boiling, such as 95° F outside on a hot day. The Celsius thermometer, where water freezes at 0° and boils at 100°, is used in some medical settings that prefer metric measurements. The Celsius thermometer is used in many clinical teaching locations, with the normal body temperature being 37° instead of the 98.6° found in the Fahrenheit scale. When the patient information is used internationally for study, the Celsius or centigrade scale is often used.



Arabic Numbers And Roman Numerals


Medication orders or prescriptions are written in both Arabic and Roman numerals, depending on the amount of medication ordered or the prescriber’s preference. Arabic numerals are those most common such as 2 for whole numbers, image as fractional numbers, or 0.53 as a decimal number.


Roman numerals, which date back to the ancient Roman Empire, use letters to represent numerical amounts. The following are the numbers depicted by Roman numerals.





Tech Note


Roman numerals are often used when writing prescriptions because these alphabetic symbols that indicate quantity are harder to alter than Arabic numerals.



Roman Numeral Use


The rules for using Roman numerals are as follows:



• When a numeral is repeated, the value of the number is the number of times for the repetition to provide the needed number (e.g., III = 3).


• A numeral may be repeated up to three times in succession and no more (e.g., IIII as 4 is incorrect; the correct way to express 4 is IV).


• The letters V, L, and D are not repeated (e.g., VV is incorrect for 10).


• When a numeral of lower value is placed following a larger numeral value, the smaller numeral is added to the larger numeral (e.g., XI = 11, VI = 6). Only I, X, or C can be used in this manner.


• If the smaller numeral value is placed before the larger numeral value, the smaller value is subtracted from the larger numeral value (e.g., IV = 5 − 1, or 4). Again, only I, X, or C may be used in this manner.


• Only one smaller number may be placed either before a larger number (e.g., IIX is not 8; rather, 8 is expressed as VIII).


• The subtracted number must be no less than one tenth of the value of the number from which it is subtracted (e.g., X may be placed before a C or an L but cannot be used with M or D. Thus 49 must be stated as XLIX rather than IL).


• Use the largest value numerals possible (e.g., 15 is XV, not VVV or XIIIII).


• Use I before V and X (the next two higher numerals). The numeral X may be used before L and C (the next higher numerals). Although seldom used, C may be used before D and M.


• image is used as an abbreviation for one-half.


• Medical notations of Roman numerals are usually written in the lower case with a line drawn over the numerals to prevent misinterpretation. The lowercase “i” has the line usually with the dot above the line, not below as commonly written.




Converting Roman Numerals to Arabic Numbers


To change Roman numerals into Arabic numbers, divide the entire Roman numeral into the groups of letters that indicate a number, such as XIV where X = 10 and IV = 4. So the Roman numeral XIV = 14.


An example of changing Roman numerals to Arabic numbers is as follows:



Example 3-2


Change XLVII to an Arabic number. Divide the number into XL and VII. XL means to subtract 10 (X) from 50 (L) or 40, whereas VII is 5 (V) + 1 (I) + 1 (I), or 7. When the numbers are placed together, XLVII (XL + VII) is 47.


Another example for changing Arabic numbers to Roman numerals follows:



Example 3-3


Remember that image is the same as image. Change image into an Arabic number by first dividing the Roman numeral into separate parts. Thus image is xix, or 10 (x) + 9 (ix) (10 − 1) + image (image), or image. To change an Arabic number to a Roman numeral, image would be x (10) + v (5) + i (1) + image (image), or image

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Related posts:

  1. Assessment of Mathematical Calculation Skills Needed for Pharmacy Technicians
  2. Interpretation of Medication Labels and Orders
  3. Calculation of Mixtures from Stock Medications
  4. Review of Basic Mathematical Skills

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Jun 24, 2016 | Posted by in PHARMACY | Comments Off on Conversion of Clinical Measurements of Numbers, Time, and Temperature

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