1. Metric System International System of Units (SI)

2. The Language of Measurement StandardStandard: an exact quantity against which comparisons can be made (any number) UnitUnit: a label that follows the measurement to give it value (meter, liter) Standard of comparison:Standard of comparison: comparing the size of an object with that of a known standard. (2 liters, 10 meters, 5 grams)

3. Science Uses Metric Units World scientists use the International System of Units (SI) because it uses less units and is convenient and universal. Metric Units Meter Length Liter Liquid Volume Gram Mass Newton Force/Weight Second Time Celsius & Kelvin Temperature

4. Matter Everything is made of matter All matter has properties that can be observed and described Physical Properties Chemical Properties Color Shape Hardness measure One way to observe physical properties is to measure them!

5.  Measured using a meter ruler or meter stick meter - m  Basic unit for length:meter - m Length - 26 cm

6. m²Standard SI Unit – square meter - m² Formula: Area equals length times width: A = l x w AREA Length – 8 cm Width 3 cm Area: 8 x 3 = 24cm²

7. m³Standard SI Unit – cubic meter - m³ : V = l x w x hVolume equals length times width times height: V = l x w x h Length – 10 m Width = 5 m Height: 3 m Volume: 10 x 5 x 3 = 150 m³

8. Usually measured in Liters (L) Tools: Graduated Cylinder Beakers

9. Amount of matter in an object Standard SI Unit: kilogram and gram Tool: Triple Beam Balance

10. Amount of mass a material has for its volume Often compared with the density of water less dense: float more dense: sink Frozen water expands and becomes less dense = floating ice cubes D = M/V means Mass divided by Volume

11. pushpull A push or pull on an object Weight is the measure of the force of gravity acting on an object Strength depends on the mass of the object and the distance between them Newtons (N) SI Unit: Newtons (N) Weight measured on a spring scale

12. Kelvin (K) Celsius (C) Measured using a thermometer 2 scales used in science Note: The Fahrenheit temperature scale still used in U.S. weather forecasts.

13. A measurement of the period between two events. Not a property of matter SI Unit: Second In one second, light can travel about 7 ½ times around the earth at the Equator. Speed of light: 186,300 per second Most accurate: atomic clock at the National Bureau of Standards in Washington, DC

14. “WHY DO I NEED TO KNOW THE METRIC SYSTEM?” All countries in the world use the Metric System… except Burma (Myanmar) and the United States National Bureau of Standards in Washington, DC sets accurate measurement standards for science, industry and commerce Industries that sell or buy goods in other countries must use SI units to compete in those countries.

15. Accuracy, Estimation, and Precision ACCURACY: depends on how close your value is to the actual or accepted value ESTIMATION: a valuable skill that saves time! –It can be improved with practice. PRECISION: the degree of exactness with which the object is measured. –Depends on the measuring instrument. –Can’t improve with practice. –Can only be as precise as the measurement instrument. –Does not guarantee accuracy!