Basic Math Refr esherNursing required competency in mathematical skills in order for you to be able toadminister medications to your patients safely. Use the following basic mathrefresher to build the foundation for developing proficiency in the mathematicalskills necessary for nursing. Roman Numerals I=1 V=5 X=10 C=100 D=500 M=1000Roman Numerals - General RuleThe basic form is to place the larger numerals to the left and add other numerals.Example: XXXIII = 33, which is (XXX = 30) + (III = 3) = 33Note: If there seems to be several ways of writing a number, use the shorter form.XXI – 21, which is (XX=20) + (I = 1) = 21, not XVVI (X = 10 + V = 5 + V = 5 + I = 1)
Basic Math Refr esherRoman Numerals – ExceptionThe exception to the basic form is if smaller numerals precedes a larger numeral, the smaller should be subtracted from the larger.Example: IX = 9(I = 1) - (X = 10) = 1 – 10 (really 10 – 1) = 9Note: only one smaller numeral can precede a larger numeral.Example: XCV = ((X = 10) – (C = 100)) + (V = 5) = 95 correct, not IXCV (two smaller numerals preceding the C (100)).Note: Roman numerals can be written in upper case and lower case.Examples: IV or iv = 4
Basic Math Refr esher FractionsA fraction is a way of representing division of a whole into parts. It has theform: Numerator Denominatorwhere the Numerator is the number of parts chosen and the Denominator isthe total number of parts.
Basic Math Refr esherFRACTION TYPESThere are 3 different types of fractions:Proper Fractions: Numerator < Denominator - Proper fractions havethe numerator smaller than the denominator. Examples are ½, ⅖, or ⅞.Improper Fractions: Numerator > Denominator or Numerator =Denominator - Improper fractions have the numerator greater or equal tothe denominator. Examples are 5/5 or 7/2.Mixed Fractions - Mixed fractions have a whole number plus afraction. Examples are 2 and ⅕ or 123 and ⅞.
Basic Math Refr esher Decimals Decimals and the conversion of decimals to fractions and fractions to decimals is a necessary skill in the nursing profession. Relative Values of Decimals Values on the left side of the decimal are increasing in value 100.00 is larger than 10.00 Values on the right side of the decimal are decreasing in value 0.1 is larger than 0.01
Basic Math Refr esher Relative Value of Decimals 1234.5678Thousands Ten Thousandths Hundreds Hundredths Tens Thousandths Ones Tenths
Basic Math Refr esherConvert a decimal into a fraction - example.25 = 25 hundredths (5 is in the hundredths position) = 25 100 (reduce the fraction) = 1 4
Basic Math Refr esher Rounding Rules ml or cc Tablets If the answer is < 1cc (or ml) then Tablets, as a rule, can only be round to the nearest 100th. given whole or broken in half. Ex: 0.376 = 0.38 cc (or ml) If the answer is > 1cc (or ml) then Round to the nearest half (0.5) round to the nearest 10th. Ex: 1.45 = 1.5 tablets 1.2 = 1 Ex: 1.57 = 1.6 cc (or ml) tabletRound at the end of the problem, when you get to the answer (exception is whenyou’re converting pounds to kilograms (kg)) then you should round to the nearest tenthas soon as you convert, then complete the problem. (2.345 = 2.4)
Basic Math Refr esher Rounding RulesBasic Rounding Remember • RouIf the number is ≥ 5 then round up. Round at the end of the problem.Ex: 1.57 = 1.6 1.45 = 1.50.686 = 0.69If the number is < 5 then round down.Ex: 0.543 = 0.54Converting pounds and kilogramsRound to the nearest 10th. The exception to this rule is when you areEx: 120 pounds = 54.54 or 54.5 kg converting pounds to kgs. Always convert and round to the nearest 10th and then complete the problem.