1. Measurements in Astronomy For really, really big and faraway things!!!

2. U.S. Customary (English Units) Units of Distance Inch – good for measuring little things, like a pencil (thumb) Foot – 12 inches – good for measuring things like a room or a car (human foot) Yard – 3 feet – good for measuring things like a swimming pool or a football field (nose to finger) Mile – 1760 yards or 5280 feet – good for measuring distances between cities (1000 paces of Roman Legion)

3. We ’ re used to thinking in these measurements, but it ’ s much harder to do calculations between them. Who wants to divide by 12 or multiply by 1760? Not you, I bet! That ’ s why metric is awesome!!!

4. The Metric System Also called the International System of Measurement – Why? Because every other country in the world uses it! If you know the prefixes of metric words, you ’ ll know how to convert between different units.

5. Prefixes to know Centi = 100 (cents in a dollar, years in a century) Milli = 1000 (years in a millenium) Kilo = 1000 (but kilo is really big, and milli is really small) So… – 1000 millimeters in a meter – 100 centimeters in a meter – 1000 meters in a kilometer

6. Metric System Chart mnemonicMetric Conversion Scientific Notation KingKilometer1,000 m10 3 Henry Hectometer 100 m10 2 Dies Dekameter 10 m10 1 While Standard (meter, liter, gram) 1 m10 0 DrinkingDecimeter.1 m10 -1 Chocolatecentimeter.01 m10 -2 Milkmillimeter.001 m10 -3

7. FYI Prefixes in metric are not just used for distance (meters). They are also used for mass (grams) and volume (liters) too! Isn ’ t that easy?!?

8. Scientific Notation Helps scientists make really, really big and really, really small numbers easier to write. Who wants to write 1,700,000,000,000,000,000,000,000 when you can write 1.7 x 10 24, or 0.0000000000000000000000000002 when you can write 2 x 10 -28 ?

9. Skill Builder: Scientific Notation Follow the four steps in the skill builder to fill in the chart on page 1, then answer the questions under part 2.