Overview
This lecture introduces the metric system's base unit for distance (the meter), its common prefixes for larger and smaller distances, and explains when to use each unit.
Metric System Base Unit
- The base unit of distance in the metric system is the meter (m).
- Average human height ranges from 1.5 to 2 meters.
- The meter is used to measure heights, wingspans, and similar lengths.
Larger Metric Units
- The kilometer (km) is commonly used for city-to-city distances and is equal to 1,000 meters.
- Example: 5 kilometers (5 km) equals 5,000 meters.
- Hectometer (hm) is 100 meters, and dekameter (dam) is 10 meters, but both are rarely used.
Smaller Metric Units
- Decimeter (dm) is 1/10 of a meter or 0.1 meters; 1 meter = 10 decimeters.
- Centimeter (cm) is 1/100 of a meter or 0.01 meters; 1 meter = 100 centimeters.
- Millimeter (mm) is 1/1,000 of a meter or 0.001 meters; 1 meter = 1,000 millimeters.
- Millimeters and centimeters are commonly used for small objects and precise measurements.
Metric Prefixes and Usage
- Prefixes indicate multiples or fractions of the meter and are used in other metric measurements (like volume).
- Use different units depending on the scale of the object you are measuring.
Key Terms & Definitions
- Meter (m) — Base unit of distance in the metric system.
- Kilometer (km) — 1,000 meters.
- Hectometer (hm) — 100 meters (rarely used).
- Dekameter (dam) — 10 meters (rarely used).
- Decimeter (dm) — 0.1 meter or 1/10 of a meter.
- Centimeter (cm) — 0.01 meter or 1/100 of a meter.
- Millimeter (mm) — 0.001 meter or 1/1,000 of a meter.
Action Items / Next Steps
- Review and memorize the metric prefixes and their values.
- Practice converting between different metric units.