4-1 © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Chapter 4 Metric System PowerPoint ® Presentation to accompany: Math and Dosage Calculations for Healthcare Professionals Fourth Edition Booth, Whaley, Sienkiewicz, and Palmunen

4-2 © 2012 The McGraw-Hill Companies, Inc. All rights reserved. 4.1 Write measurements in metric notation. 4.2 Convert metric units by moving the decimal. Learning Outcomes

4-3 © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Key Terms  Centi (c)  Gram (g)  Kilo (k)  Liter (L)  Meter (m)  Micro (mc)  Milli (m)

4-4 © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Introduction  The metric system is the most commonly used system of measurement in the healthcare system.  It is essential to accurately convert units within the metric system when performing dosage calculations.

4-5 © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Metric System  Most widely used system of measurement  Basic units Meter – length for measurements of height, circumference, wound size Gram – weight Liter - volume Dosage calculation

4-6 © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Metric System (cont.)  Meter and gram are abbreviated with lowercase letters.  Liter is abbreviated with an uppercase L. Basic Units of Metric Measurement

4-7 © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Metric Notation  It is based on multiples of 10.  The prefix before the basic unit indicates size.  A meter divided by 1000 provides equal lengths of one millimeter.

4-8 © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Metric Notation (cont.) PrefixLengthValue kilo- (k)kilometer (km) 1 km = 1000 m (basic unit)meter (m)1 m centi- (c)centimeter (cm) 1 cm = = 0.01 m milli- (m)millimeter (mm) 1 mm = = m micro- (mc) micrometer (mcm) 1 mcm = = m Common Metric System Prefixes

4-9 © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Metric Notation (cont.) Prefix Length (meter) Weight / Mass (gram) Volume (liter) kilo- (x 1000)kilometer (km) kilogram (kg)kiloliter (kL) centi – (÷ 100) centimeter (cm) centigram (cg) centiliter (cL) milli- (÷ 1000) millimeter (mm) milligram (mg) milliliter (mL) micro- (÷ 1,000,000) micrometer (mcm) microgram (mcg) microliter (mcL) Combining Prefixes and Units

4-10 © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Rule 4-1 Use Arabic numerals with decimals to represent any fractions. Example: Write 1.25 g to represent 1 1/4 g. Metric Notation (cont.)

4-11 © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Rule 4-2 If the quantity is less than 1, include a 0 before the decimal point. Delete any other zeros that are not necessary.  Example: Do not write.750; write 0.75 Metric Notation (cont.)

4-12 © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Rule 4-3 Write the unit after the quantity with a space between the unit and the quantity. Example: Write 30 mg, not mg 30. Metric Notation (cont.)

4-13 © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Rule 4-4 Use lowercase letters for metric abbreviations. However, use an uppercase L to represent liters.  Example: Write mg, not MG.  Example: Write mL, not ml. Metric Notation (cont.)

4-14 © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Practice Which of these is the correct metric notation for six and two-eighths milliliters? a. 6.28mL b. ml 6.25 c. 6 mL d mL Answer

4-15 © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Rule 4-5 Rule 4-5 To convert a quantity from one unit of metric measurement to another: 1. for larger to smaller unit – move the decimal point to the right; 2. for smaller to larger unit – move the decimal point to the left. Converting within the Metric System

4-16 © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Practice 1. Convert 4 L to mL. 2. How many meters = 75 mm? ANSWER: 4 L = L = 4000 mL ANSWER: 75 mm = m

4-17 © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Error Alert! Remember:  The larger the unit, the smaller the quantity.  The smaller the unit, the larger the quantity. 1 dollar bill = 4 quarters = 100 pennies 100 pennies = 4 quarters = 1 dollar bill Example

4-18 © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Error Alert! When converting from one unit to another, pay close attention to the decimal point.  To convert milligrams (mg) to micrograms (mcg) multiply by 1000; move decimal three places to the right. Example

4-19 © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Practice 4 g = x mg 6.5L = x mL 7586 mm = x m 455 mg = x g mL = x L 1.5 m = x cm ANSWER: 4000mg ANSWER: 6500 mL ANSWER: m ANSWER: g ANSWER: L ANSWER: 150 cm

4-20 © 2012 The McGraw-Hill Companies, Inc. All rights reserved. In Summary  In this chapter you learned to: write measurements in metric notation; convert metric units by moving the decimal.

4-21 © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Apply Your Knowledge What is the correct metric notation for: 1. Six-hundreths kilograms 2. Five hundred sixty-five centimeters 3. Fourteen and one-half liters ANSWER: 0.06 kg ANSWER: 565 cm ANSWER: 14.5 L

4-22 © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Apply Your Knowledge Convert 5.0 mcg to mg. ANSWER: mg Convert 43 kg to g. ANSWER: 43,000 g

4-23 © 2012 The McGraw-Hill Companies, Inc. All rights reserved. End of Chapter 4 Practice is the best instruction of them all. ~Publilius Syrus