Overview
This lecture introduces the metric system, focusing on common prefixes, the three base units (meter, liter, gram), and their abbreviations.
Metric System Prefixes
- Kilo means 1,000; hecto means 100; deca means 10.
- Deci means one-tenth (1/10); centi means one-hundredth (1/100); milli means one-thousandth (1/1000).
Base Units in the Metric System
- The three base units are meter (distance), liter (capacity), and gram (weight).
- A mnemonic for the base units is "My Large Giraffe" (Meter, Liter, Gram).
Meter and Its Prefixes
- A meter is slightly longer than a yard (about 39 inches).
- Kilometer = 1,000 meters; hectometer = 100 meters; decameter = 10 meters.
- Decimeter = 1/10 meter; centimeter = 1/100 meter; millimeter = 1/1000 meter.
Liter and Its Prefixes
- A liter is used for measuring capacity (e.g., beverage bottles).
- Kiloliter = 1,000 liters; hectoliter = 100 liters; decaliter = 10 liters.
- Deciliter = 1/10 liter; centiliter = 1/100 liter; milliliter = 1/1000 liter (like an eyedropper).
Gram and Its Prefixes
- A gram is about the weight of a paperclip or chalk.
- Kilogram = 1,000 grams (about 2.2 pounds, like a textbook).
- Hectogram = 100 grams; decagram = 10 grams.
- Decigram = 1/10 gram; centigram = 1/100 gram; milligram = 1/1000 gram (e.g., aspirin dose).
Metric Abbreviations
- Kilometer: km; hectometer: hm; decameter: dam (note the "k" in dam for deca).
- Decimeter: dm (no "k"); centimeter: cm; millimeter: mm.
- Kiloliter: kL; hectoliter: hL; decaliter: daL; deciliter: dL; centiliter: cL; milliliter: mL.
- Kilogram: kg; hectogram: hg; decagram: dag; decigram: dg; centigram: cg; milligram: mg.
Key Terms & Definitions
- Base Unit — The main measurement for a category: meter (length), liter (volume), gram (mass).
- Prefix — Word part added to the base unit to indicate size (e.g., kilo-, centi-, milli-).
- Abbreviation — Shortened form of a metric unit (e.g., cm for centimeter).
Action Items / Next Steps
- Memorize the metric prefixes and their values.
- Learn the abbreviations for each unit and prefix combination.
- Practice converting between metric units using the prefixes.