Nursing Preparation Study Guide

Nursing Preparation Study Guide

Chapter 3: Math – Part 1 3.1 Order of Operations Mathematical operations must be performed in the correct order when you are performing calculations with numbers. First, you must perform the operations in parenthesis. From there you would then simplify the exponents and then complete any multiplication or division from left to right. Finally addition or subtraction is then completed. Parenthesis – (anything in here first) • Exponents – Then %& ()*) or √under here • Multiplication and Division – next × or ÷ • Addition and Subtraction – finally + or – or ± Use the mnemonic device PEMDAS (Please Excuse My Dear Aunt Sally) to help you to remember the order of operations. Example Example Simplify the following expression: 5 + 5 × 5 − 5 ÷ 5 = Simplify the following expression: (2 + 2) × 2 8 = a. a.

9 b. 29 c. 5 d. 0

10 b. 4 c. 8 d. 16

The correct answer is B. To simplify this expression, go through order of operations. 5 + 25 − 5 ÷ 5 = 5 + 25 − 1 = 5 + 24 = 25

The correct answer is D. To simplify this expression, go through order of operations. 4 × 2 8 = 4 × 4 = 16

3.2 Fractions 3.2.1 Addition and Subtraction of Fractions Begin by converting any mixed numbers (if there are any) into improper fractions. This means converting any number that represents the sum of a whole number and a proper fraction into a fraction whose numerator is greater than the denominator. Then you will determine the least common denominator (LCD) for the fractions. The LCD is the smallest common multiple of the denominators. This is the least number that both denominators divide into evenly. Once you have the LCD, then you will rewrite each fraction as an equivalent fraction with the least common denominator. Then you will add or subtract the numerators, while keeping the common denominator the same. Lastly, check to make sure that the fraction is the simplest fraction. This means that the only common factor between the numerator and the denominator is 1.

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