1. Measurement

2. Scientific Notation is a way of expressing a value as the product of a number between 1 and 10 and a power of 10. It makes very large or very small numbers easier to work with. 650,000 = 6.5 x 10 5 0.00000000754 = 7.5 x 10 -9

3. Scientists use a set of measuring units called SI, or the International System of Units. There are seven base units used in science and several derived units, such as volume, area, density, and pressure. SI comes from France. There it is the Systeme International d’Unites. It was originally developed in 1791.

4. Base Units QuantityUnitSymbol LengthMeterm MassGramg TemperatureKelvinK Amountmolemol CurrentampereA Timeseconds Luminous Intensity candelacd

5. DERIVED UNITS are made from combinations of base units. Some of the derived units we use are density, volume, and pressure.

6. The metric unit for a quantity is not always convenient to use, so metric PREFIXES are added to the unit to indicate how many times a unit should be multiplied or divided by 10.

7. A CONVERSION FACTOR is a ratio of equivalent measurements used to convert a quantity expressed from one unit to another. 1000 m = 1 km so, 8480 m * 1 km = 8.480 km 1000m

8. PRECISION is a gauge of how exact a measurement is. SIGNIFICANT FIGURES are all the digits that are known in a measurement, plus the last digit that is estimated.

10. ACCURACY is the closeness of a measurement to the actual value of what is being measured. So you can be precise and not be accurate. For example, if the clock says that it is 4:01:52 right now that time is very precise – but NOT accurate.

11. A THERMOMETER is an instrument that measures temperature. The two most common scales are the FAHRENHEIT and CELSIUS. In science, the KELVIN is also used.

12. We use Kelvin and Celsius because it is much easier to convert from one to the other. K = o C + 273 If we used Celsius and Fahrenheit: o F = (9/5)* o C + 32.0 o

13. Prefixes PrefixSymbolMeaningMultiply By Kilok10 3 1000 hectoh10 2 100 dekada10 1 10 decid10 -1.1 centic10 -2.01 millim10 -3.001 micro  10 -6.000001