Metric System AKA How to measure stuff in

Metric System AKA – How to measure stuff in Science class!

Equivalencies (English System) • • 12 inches = 1 foot 3 feet = 1 yard 5, 280 feet = 1 mile 2 pints = 1 quarts 4 quarts = 1 gallon 16 ounces = 1 pound 24 hours = 1 day

Why Do We Use the Metric System? • Easy to Use – based on powers of 10 • Scientists from around the world needed a standardized method of measuring (to duplicate experiments) • Also known as the International System of Units (SI Units)

What Do These Countries Have in Common? Burma United States Liberia

How Do We Use the Metric System? • Two Parts: – Base Units – these are your starting points – Prefixes (pre- means “before”) – to express quantities that are larger and smaller than the base units, you add a prefix to the base unit • Prefixes represent multiples of 10 • Sometimes base units are written by themselves; other times, the base units have a prefix attached

Common Metric Base Units Metric Base Unit Used to Measure Abbreviation meter Length m Liter Volume L gram Mass (similar to weight) g

Common Metric Prefixes Prefix Abbreviation Numerical Equivalent kilo- k 1, 000 hecto- h 100 deka- da 10 Base Unit m, L, g 1 deci- d 1/10 (0. 1) centi- c 1/100 (0. 01) milli- m 1/1000 (0. 001)

Examples • Base units written alone: – m (meter) – L (Liter) – g (gram) If there is only a one letter abbreviation used, then you will have a base unit • Base units with prefixes: – km (kilometer) – m. L (milliliter) – dag (dekagram) If there is a two- or three-letter abbreviation used, then you will have a prefix listed before the base unit (last letter will ALWAYS be the base unit abbreviation)

Examples • If you have one meter, you simply write 1 m • If you have 10 meters, you can write 10 m, or you can express this number as 1 dekameter (1 dam) • If you have 100 meters, you can write 100 m, or you can express this number as 1 hectometer (1 hm) • If you have 1000 meters, you can write 1000 m, or you can express this number as 1 kilometer (1 km)

More Examples • If you have 1/10 of a meter, you can write 1/10 m, or you can express this number as 1 decimeter (1 dm) • If you have 1/100 of a meter, you can write 1/100 m, or you can express this number as 1 centimeter (1 cm) • If you have 1/1000 of a meter, you can write 1/1000 m, or you can express this number as 1 millimeter (1 mm)

How to Remember Metric Prefixes • Mnemonic Device – a saying that is used to help a person remember something • King Henry Died by Drinking Chocolate Milk • Kilo, Hecto, Deka, (Base), Deci, Centi, Milli

Metric Line • Used to help convert metric measurements kilo- hecto- deka- base deci- centi- milli-

Using the Metric Line • Convert 160. 3 centimeters to decimeters – 1. Find the decimal point – 2. Find your starting prefix – 3. Move from your starting prefix to your ending prefix – 4. Move the decimal point accordingly kilo- hecto- deka- base deci- 160. 3 cm (centi-) (centi- to deci-) 16. 03 dm centi- milli-

Try Some! • Convert 25. 9 cm to m (meters) – Centimeters to meters (base) on the metric line is 2 spaces to the left – Move your decimal point two spaces to the left – Don’t forget to change your units! – 25. 9 cm =. 259 m

Try Some! • Sometimes, zeroes must be used as placeholders • Convert 8. 7 cm to hm (hectometers) – Centimeters to hectometers on the metric line is 4 spaces to the left – Move your decimal point 4 spaces to the left – Add zeroes as placeholders – 8. 7 cm =. 00087 hm