Introduction to the Metric System

History Called Systeme International d’Unitès, Revised periodically or SI - International System of Units Revised periodically by International Bureau of Weight and Measures

Customary Units of Measurement The English System a collection of functionally unrelated units Difficult to convert from one unit to another Ex. 1 ft = 12 inches = 0.33 yard = 1/5280 miles Customary Units length - inch, foot, yard, mile weight/mass - ounce, pound volume - teaspoon, cup, quart, gallon temperature - degrees Fahrenheit , KELVIN time - minutes, hours

Advantages of Using the Metric System Universal - used everywhere by all scientists to communicate by all industrialized nations except United States U.S. loses billions of dollars in trade

Advantages of Using the Metric System Simple to use A few base units make up all measurements length - meter mass - grams volume - liters temperature – degrees Celsius time - seconds

Advantages of Using the Metric System There is only one unit of measurement for each type of quantity To simplify things, very small and very large numbers are expressed as multiples of the base unit. Prefixes are used to represent how much smaller or larger the quantity is compared to the base unit. Easy to convert from one unit to another shift decimal point right shift decimal point left

Advantages of Using the Metric System Same set of prefixes for all units Greek - multiples of the base kilo - 1000 × the base hecto - 100 × the base deka - 10 × the base Latin - fractions of the base deci - tenths of the base centi - hundredths of the base milli - thousandths of the base

Metric Prefixes

Units of Length Length - the distance between two points standard unit is meter (m) long distances are measured in km Measured using a meter stick or ruler

Prefixes and Units of Length centimeter - cm 1 m = 100 cm 1 cm = 1/100th m millimeter - mm 1 m = 1000 mm 1 mm = 1/1000th m 10 mm = 1 cm measures very small lengths kilometer - km 1 km = 1000 m 1 m = 1/1000th km measures long distances

Measuring Mass Mass - the quantity of matter in an object standard unit is gram (g) Measured using a digital scale or triple beam balance

Measuring Volume and Capacity Volume - the amount of space occupied by an object standard unit is liter (L) 1 L = 1000 ml = 1000 cm3 = 1 dm3 Measured using a graduated cylinder Capacity - a measure of the volume inside a container

Prefixes and Units of Volume STOP HERE Liter - L 1 L = 1000 milliliters 1 L = 1000 cubic centimeters = 1000 cm3 milliliter - mL measures small volumes 1 mL = 1 cubic centimeter 1000 mL = 1 Liter 1 mL = 1/1000th liter kiloliter - kL measures large volumes 1 kL = 1000 L

Unit Conversion Practice Example: Convert 4 ounces to kilograms.