DOSAGE CALCULATIONS PACKET SUMMER AND FALL

MATH AND DOSAGE CALCULATIONS PACKET SUMMER AND FALL 2017 Unit I – Basic Mathematics Review This unit will review fractions, decimals, percentage, and ratio and proportion. FRACTIONS Definition: A fraction is a part of a whole number. A fraction has 2 parts, the top number is called the numerator and the bottom number is called the denominator. Example: ½ = 1 is the numerator and 2 is the denominator. There are 4 types of fractions: 1. Proper fractions – the numerator is less than the denominator and the fraction has a value of less than 1. Example: ½. 2. Improper fractions – the numerator is larger than or equal to the denominator and has a value of 1 or greater than 1. *Example: 6/5 *An improper fraction must be reduced to the lowest terms by dividing the numerator by the denominator. (Therefore, 6/5 should be “reduced” to 1 1/5 or one and one-fifth.) 3. Complex fractions – the numerator or denominator may be either a fraction or a whole number. The value may be less than, greater than, or equal to 1. Example: ½ or ½ 2 ¾ 4. Mixed number – there is a whole number and a fraction combined with a value greater than 1. **Example: 3 ½. **A mixed number must be reduced to the lowest terms also. To change a mixed number to an improper fraction, multiply the whole number by the denominator and add the numerator. *** Example: 3 ½ = (2 X 3) + 1 = 7 2 2 *** Remember: Unless asked to give an answer as an improper fraction, never leave it as such. Therefore, 7/2 should be reduced to 3 ½ or three and one half.