Systems of Measurement Chapter 3 Systems of Measurement © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

Metric System The metric system is the most common and the only standardized system Adopted in 1799 in France Most precise Based on powers of 10 3 parameters associated with Rx and administration of meds weight, length, and volume © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

Metric System Weight is the most utilized; the base for weight is gram Volume will usually be in reference to liquids and base unit is liter Length is the least utilized measurement but will be used often to measure height and base unit is meter; most used will be cm (centimeters) and mm (millimeters) © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

Metric Prefixes Micro = one millionth or 0.000001 or of the base unit Milli = one thousandth or 0.001 or of the base unit Centi = one hundredth or 0.01 or of the base unit © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

Metric Prefixes (Continued) Deci = one tenth or 0.1 or of the base unit Kilo = one thousand or 1,000 times the base unit © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

International System (SI) of Metric Units and Abbreviations Weight Gram (base unit) – g Milligram – mg Microgram – mcg (µg) Kilogram – kg © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

International System (SI) of Metric Units and Abbreviations Volume Liter (base unit) – L (ℓ) Milliliter – mL (mℓ) Cubic centimeter – cc © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

International System (SI) of Metric Units and Abbreviations Length Meter (base unit) – m Centimeter – cm Millimeter – mm © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

Comparing Common Metric Units PREFIX Kilo- Hecto- Deca- BASE Deci- Centi- Milli- Decimilli- Centimilli- Micro- Weight kilogram gram milligram microgram Volume liter deciliter milliliter Length meter centimeter millimeter Value to Base 1,000 100 10 1.0 0.1 0.01 0.001 0.0001 0.00001 0.000001 © Cengage Learning 2013 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

Remembering Order GRAM LITER METER kilo hecto deca BASE deci centi milli K H D C M “King Henry Died from a Disease Called Mumps” © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

k h d (BASE) d c m BASE is meter, liter, or gram BASE is the only letter that can stand alone To convert metric to metric, use the supplied chart © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

k h d (BASE) d c m k h d Base d c m To convert 1 gram to centigram, you move the decimal as you would in the chart k h d Base d c m So 1 gram = 1.00 = 100 centigrams © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

Rules of Metric Notation Unit or abbreviation always follows amount 5 g NOT g 5 Decimals used to designate fractional metric units 1.5 mL, NOT mL © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

Rules of Metric Notation Use a zero to emphasize decimal point for fractional metric units less than 1 0.5 mg, NOT .5 mg Will prevent potential dosage error If 5 mg was misinterpreted for 0.5 mg, the dosage would be 10 times too much and could be lethal © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

Rules of Metric Notation Omit unnecessary zeros 1.5 g, NOT 1.50 g This is a critical rule When in doubt, double-check Ask writer for clarification © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

Metric Measurements and Equivalents Weight Unit Abbreviation Equivalents gram g 1 g = 1,000 mg milligram mg 1 mg = 1,000 mcg = 0.001 g microgram mcg 1 mcg = 0.001 mg = 0.000001 g kilogram kg 1 kg = 1,000 g k h d Base d c m Check these by using this chart © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

Metric Measurements and Equivalents Length Unit Abbreviation Equivalents meter m 1 m = 100 cm = 1,000 mm centimeter cm 1 cm = 0.01 m = 10 mm millimeter mm 1 mm = 0.001m = 0.1 cm k h dk Base d c m © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

Metric Measurements and Equivalents Volume Unit Abbreviation Equivalents liter L (or ℓ) 1 L = 1,000 mL milliliter mL (or mℓ) 1 mL = 0.001 L = 1 cc cubic centimeter cc 1 cc = 1 mL = 0.001 L k h dk L d c m cc Again, this chart really helps © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

Unsafe Abbreviations Many health organizations have prohibited the use of “cc” as it has been confused with zeros and units Micrograms should always be abbreviated “mcg” not “µg” The word “unit” must be spelled out; it cannot be abbreviated “U” Review CAUTION blocks in your book for more information © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

Units Standardized amount needed to produce a desired effect Used to measure unit of potency Vitamins Chemicals © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

Milliequivalents (mEq) One thousandth of an equivalent weight of a chemical Used when referring to serum electrolytes © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

Household System of Measurement Unit Abbreviation Equivalents drop gtt teaspoon t (or tsp) tablespoon T (or tbs) 1 T = 3 t ounce (fluid) fl oz 2 T = 1 oz ounce (weight) oz 1 lb = 16 oz cup 1 cup = 8 oz pint pt 1 pt = 2 cups quart qt 1 qt = 4 cups = 2 pt © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

Approximate Equivalents 1 t = 5 mL 1 T = 3 t = 15 mL = ½ fl oz 1 fl oz = 30 mL = 6 t 1 L = 1 qt = 32 fl oz = 4 cups 1 pt = 16 fl oz = 2 cups 1 cup = 8 fl oz = 240 mL 1 kg = 2.2 lb 1 in = 2.5 cm © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.