Units of Measure

1. Units of Measure Section 1.2 Metric Length

2. Pre-View 1.2 • Meter – the standard SI unit for measuring length. • Ruler or meter stick – tool used to measure length in centimeters or millimeters

3. The smallest marks on a ruler or meter stick indicate millimeters (mm). • There are 1000 mm in one meter. • The longer marks on a ruler or meter stick show centimeters (cm) – 10 mm = 1 cm, and there are 100 cm in one meter. • Longer lengths are measured in kilometers (km), which are 1000 meters.

5. 10 mm or 1 cm

6. SI unit of Length: Kilometer (km) • When to use it… • Use kilometers for long distances. • Example: • The distance from Birmingham to Anniston is about 106 km

7. SI unit of Length: Meter (m) • When to use it… • Use meters instead of feet or yards. • Example: • The height of an average room from floor to ceiling is about 3 m

8. SI unit of Length: Centimeter (cm) • When to use it… • Use centimeters instead of inches. • Example: • One inch is 2.54 cm. The width of notebook paper is about 21.6 cm

9. SI unit of Length: Millimeter (mm) • When to use it… • Use millimeters for small but visible lengths. • Example: • The diameter of an average pencil is 7 mm

10. SI unit of Length: Micrometer (μm) • When to use it… • Use micrometers to measure very small or microscopic dimensions. • Example: • The length of a paramecium is about 50 μm