The Metric System When a man's knowledge is not in order, the more of it he has the greater will be his confusion. -Herbert Spencer http://illuminations.nctm.org/LessonDetail.aspx?ID=L861

Why use the metric system? Developed in the 1790’s during the French Revolution Scientists and educated scholars needed to come up with a uniform (same) system of measurement that could be used worldwide To prevent confusion!

What do we use today? Système International (SI) The SI is a more modern form of the metric system. Both the metric system and SI are based on units of ten. A unit is an amount used to measure something.

Why is the Metric System Important? Helps scientists share and compare observations and results. All units are based on 10, which makes conversions from one unit to another easy.

When Do We Use The Metric System? Measurement

Examples of Metric Basic Units of Measurement Mass Grams Amount of matter Length Meters Linear size in space (how long an object is) Volume Liters Amount of 3-D space an object takes up Time – measured in seconds and hours These are the suffixes *at the end of the word

Examples of Metric Basic Units of Measurement Temperature Kelvin (K) Celsius (°C) How hot/cold something is Area Area = Length X Width Measure of the surface of an object Density Density = Mass/Volume How much matter is in a given volume Time – measured in seconds and hours These are the suffixes *at the end of the word

Basic Unit Meter Liter Grams

Metric Prefixes These prefixes go before the basic unit Kilo- King Hekto- Henry Deka- Dances M/G/L [Merrily] Deci- Down Centi- Central Milli- Main Street

Numerically speaking… 1000 100 10 1 0.1 0.01 0.001 = Kilo = Hekto = Deka = No Prefix (Basic Unit) = deci = centi = milli

To climb the metric ladder: move the decimal point to the left for each step you go up. Move the decimal to the right for each step you go down.

Smaller Unit? Move Right Or divide Kilo 1000 Units Larger Unit? Move Left Or multiply Hecto 100 units Deka 10 Units Basic Unit Deci 0.1 Units Centi 0.01 Units Smaller Unit? Move Right Or divide Milli 0.001 Units

Weight Vs. Mass Mass – the amount of matter (stuff) in an object Weight – the mass of the object multiplied by the acceleration of gravity OR W = m x g How does your mass and your weight change in outer space? Weight does, depends on gravity. MASS REMAINS THE SAME!