1. SI System of Measurement (known commonly as the metric system)

2. Background The English system of measurement originated in 1215 with the signing of the Magna Carta. It attempted to bring uniform measurements to world trade. In 1790, the French government appointed a committee of scientists to develop a universal measuring system.

3. It took ~10 years, and they unveiled the metric system. Property. Unit
It took ~10 years, and they unveiled the metric system. Property Unit abreviation length meter m mass gram g volume liter L time second s quantity of matter mole mol

4. The International System of Units (Systeme International d’unites) was developed in 1960 from the older system. It is the world’s most widely used system of units, both in commerce and science. A notable exception is the United States, which still uses many old units in addition to SI.

5. SI Base Units in Chemistry Quantity Name Symbol length meter m mass kilogram kg time second s amount of substance mole mol temperature Kelvin K

8. Prefixes in the SI System Prefix
Prefixes in the SI System Prefix x base unit Symbol equals base units Sci. notation Mega- dollar Md = 1,000,000 dollars = 1x kilo- dollar kd = ,000 dollars = 1x hecto- dollar hd = dollars = 1x deka- dollar dad = dollars = 1x 101 dollar dollar = dollar = 1x 100 base unit equals prefix x base unit Symbol Sci. notation 1 dollar = deci-dollars dd x dollar = centi-dollars cd x dollar = milli-dollars md x dollar = micro-dollars µd x dollar = nano-dollars nd 1x 109

9. Conversion of SI Units Use equivalencies to convert units
Conversion of SI Units Use equivalencies to convert units. Always make the bigger unit 1 and convert back to the base unit. M k h da - d c m n

10. For example: 3 km ______m___________cm__= ____ cm km m

11. 3 km m cm = cm km m s.n.= 3 x 105 cm

12. Likewise: 2. 5 mm 1 m 1 dam =. 00025 dam 1 000 mm 10 m. s. n. = 2
Likewise: 2.5 mm m dam = dam mm m s.n.= 2.5 x 10-4 dam

13. Try this one !
Convert
2.5 dg_______________= ___________ng