1. Units of Measurement

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

3. Here in America we use…..
the ENGLISH SYSTEM

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

5. 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

6. 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!!!!

7. 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).

8. 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

9. 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