Units of Measurement

All measurements must have a number and a unit!!! VERY IMPORTANT!!!! All measurements must have a number and a unit!!!

Here in America we use….. the ENGLISH SYSTEM

But EVERYONE else uses…. The Systeme International d’Unites OR International System of Units (SI Units)

Seven Base SI Units 1. Mass 2. Length 3. Time 4. Quantity What is measured… 1. Mass 2. Length 3. Time 4. Quantity 5. Temperature 6. Electric Current 7. Luminous Intensity Unit and symbol…. 1. Kilogram, kg 2. Meter, m 3. Second, s 4. Mole, mol 5. Kelvin, K 6. Amphere, A 7. Candela, cd

Derived SI Units Remember to multiply both the number and the unit!!!! Derived SI Units - combination of SI base units Example: Area = Length x Width Area = 4.0 m x 2.0 m Area = 8.0 m2 Remember to multiply both the number and the unit!!!!

Non-SI Units Non-SI Units - commonly used units that are not derived from the SI base units The most common example is the LITER used to measure volume. Also common is temperature measured in oC (Celcius).

Prefixes Prefixes - make a SI Unit smaller or larger by a factor of 10. Prefixes are attached to the front of the base unit. Ex: millimeter or kilometer

BASE UNIT gram (g) Liter (L) Meter (m) Kilo Hecto Deca BASE UNIT Deci Centi Milli k h da d c m 1000 100 10 1/10 1/100 1/1000