1. Ch. 1 The World of Physical Science Sec. 4 Measurement Unit 0 Science Process Skills

2. Measurement measurement - describes the world using numbers – types include… distance, time, speed, volume, mass estimation - an approximated measurement based on experience/comparison – uses “about” – estimation is useful when a measurement is not possible & can check that an answer is reasonable

3. Precision & Accuracy precision - how close measurements are to each other – [ex. 34 cm, 33 cm, and 35 cm are precise] – precision is also used to discuss number of decimal places a measuring tool can measure – [ex. a clock with a second hand is more precise than one without] accuracy - comparison of a measurement to the actual value – [ex. a 34 cm measurement of a 35 cm plant is accurate] measurements can be rounded when precision is not needed

4. SI Units The International System - a worldwide measurement system that uses SI units based on ten – the prefix of the unit changes each time the multiple of ten changes PrefixSymbolFactor kilok1,000 hectoh100 decada10 UNIT1 decid.1 centic.01 millim.001

5. SI Units Length length - the distance between two points – SI unit is the meter (m) – use kilometers to measure long distances - use centimeters to measure a pencil - use micrometers to measure cells Volume 1 2

6. SI Units Mass mass - amount of matter in an object – SI unit is the kilogram (kg) – can be measured using a balance (triple beam) – mass is the same on Earth and in space Weight weight - a measurement of force – SI unit is the Newton (N) – can be measured using a scale (spring) – depends on gravity, thus is different on Earth and in space 3 4

7. SI Units Temperature temperature - measure of kinetic energy (motion) of particles in matter – SI unit is the Kelvin (K) Time time - interval between two events – SI unit is the second (s) 5 6 Rate 7 rate - the amount one measurement changes in a specific amount of time [Ex: km/h, dollars/yr]

8. Drawings, Tables, & Graphs table - displays data in rows & columns for easier comprehension graph - visually organizes & summarizes data scales on graphs must be carefully constructed & analyzed - sometimes graphs use a broken scale that does not start at zero & can be misleading

9. Common Types of Graphs Line Graph line graph - shows the relationship b/w – two variables expressed in numbers – horizontal = x-axis vertical = y-axis Bar Graph bar graph - uses bars of different sizes to show relationships b/w variables – one variable is represented by categories & the other variable is represented by numbers 1 Circle Graph circle graph (pie graph) - shows parts of a whole as percentages –since a circle has 360º, you need to determine what section of 360º each part should be 2 3

10. Metric Conversions Ladder Method T. Trimpe 2008 http://sciencespot.net/

11. KILO 1000 Units HECTO 100 Units DEKA 10 Units DECI 0.1 Unit CENTI 0.01 Unit MILLI 0.001 Unit Meters Liters Grams Ladder Method How do you use the “ladder” method? 1 st – Determine your starting point. 2 nd – Count the “jumps” to your ending point. 3 rd – Move the decimal the same number of jumps in the same direction. 4 km = _________ m 1 2 3 How many jumps does it take? Starting Point Ending Point 4. 1 __. 2 3 = 4000 m

12. Try these conversions using the ladder method. 1000 mg = _______ g 1 L = _______ mL160 cm = _______ mm 14 km = _______ m109 g = _______ kg 250 m = _______ km Conversion Practice Compare using, or =. 56 cm 6 m 7 g 698 mg

13. Write the correct abbreviation for each metric unit. 1) Kilogram _____ 4) Milliliter _____ 7) Kilometer _____ 2) Meter _____ 5) Millimeter _____ 8) Centimeter _____ 3) Gram _____ 6) Liter _____ 9) Milligram _____ Try these conversions, using the ladder method. 10) 2000 mg = _______ g 15) 5 L = _______ mL 20) 16 cm = _______ mm 11) 104 km = _______ m 16) 198 g = _______ kg 21) 2500 m = _______ km 12) 480 cm = _____ m 17) 75 mL = _____ L 22) 65 g = _____ mg 13) 5.6 kg = _____ g 18) 50 cm = _____ m 23) 6.3 cm = _____ mm 14) 8 mm = _____ cm 19) 5.6 m = _____ cm 24) 120 mg = _____ g Metric Conversion Challenge

14. Compare using, or =. 25) 63 cm 6 m 27) 5 g 508 mg 29) 1,500 mL 1.5 L 26) 536 cm 53.6 dm 28) 43 mg 5 g 30) 3.6 m 36 cm