2. Using Scientific Notation  Scientific Notation is a way of expressing a value as the product of a number between 1 and 10 and a power of 10.  Scientific Notation makes very large or very small numbers easier to work with.

3.  Example: The number 300,000,000 written in scientific notation is 3.0x10 8. The exponent, 8, tells you that the decimal point is really 8 places to the right of the 3.  Example: The number 0.00086 written in scientific notation is 8.6x10 -4. The negative exponent, -4, tell you that the decimal point is really 4 places to the left of the 8.6.

4.  When multiplying numbers written in scientific notation, you multiply the numbers that appear before the multiplication signs and add the exponents.  When dividing numbers written in scientific notation, you divide the numbers that appears before the exponential terms and subtract the exponents.

5. EExample: 3.0x10 8 x 5.0x10 2 = 15x10 10 = 1.5x10 11 EExample: 1.5x10 11 = 1.5x 10 11-8 = 0.5x10 3 =5.0x10 2 3.0x10 8 3.0

6.  International System of Units  SI is built upon seven metric units, known as Base Units. › Example: The base unit for length(L) is the meter (m).  Additional SI units, called Derived Units, are from combinations of base units. › Example: The derived unit for volume (V) is cubic meters (m 3 ).

8. QuantityUnitSymbol LengthMeterM MassKilogramKg TemperatureKelvinK TimeSecondS Amount of substanceMoleMol Electric currentAmpereA Luminous intensityCandelacd

9. QuantityUnitSymbol AreaSquare meterM2M2 VolumeCubic meterM3M3 DensityKilograms per cubic meter Kg/m 3 PressurePascal (kg/mxs 2 )Pa EnergyJoule (kgxm 2 /s 2 )J FrequencyHertz (1/s)Hz Electric ChargeCoulomb (Axs)C

10. PrefixSymbolMeaningMultiply Unit by Giga-GBillion1,000,000,000 Mega-MMillion1,000,000 Kilo-kThousand1,000 Deci-dTenth0.1 Centi-cHundreth0.01 Milli-mThousandth0.001 Micro-µMillionth0.000001 Nano-nBillionth0.000000001

11.  A conversion factor is a ratio of equivalent measurements that is used to convert a quantity expressed in one unit to another unit.  Example: Convert the height of Mt. Everest, 8848 meters, into kilometers. kilo- =1000 8848m X 1km = 8.848km 1000m

12.  Precision is a gauge of how exact a measurement is.  Precision of a calculated answer is limited by the least precise measurement used in the calculation.  Accuracy is the closeness of a measurement to the actual value of what is being measured.

13.  Significant figures are all the digits that are known is a measurement, plus the last digit that is estimated. › Example: On an analog clock it may take you 5 minutes to eat a sandwich. On a digital clock it may take you 5.25 minutes to eat a sandwich. The time recorded as 5.25 minutes has three significant figures. The time recorded as 5 minutes has one significant figure. The fewer the significant figures, the less precise the measurement.

14. Measuring Temperature  A thermometer is an instrument that measures temperature, or how hot an object is.  The two temperature scales that you are probably most familiar with are the Fahrenheit scale and the Celsius scale.  Fahrenheit: water freezes at 32 degrees  Celsius: water freezes at 0 degrees  Conversion:  ºC = 5 (ºF – 32.0º) or ºF = 9 (ºC) +32.0º 9 5

15.  SI unit for temperature is kelvin (K).  Conversion: K = ºC + 273

16.  Textbook: › Section 1.3 Assessment (page 20) › Questions 1 – 6  Workbook: › Section 1.3 Measurement (pages 7-8)