2. Performing these conversions is a lot like going on a road trip.

4. Converting Metric Measurements basic unit centi- hecto- deca- kilo- deci- milli- 1 10 -1 10 -3 10 -2 10 3 10 2 10 1 To convert, move the decimal place the number of stairs you step on in the direction you are traveling. Example: 3.75 km = ? mm ? = 3,750,000 mm

5. Use dimensional analysis when converting between other units. zEx: How many inches are in 1500 meters?

6. Scientific Notation Scientist use special notation to express very large or very small numbers. Example I: 300,000,000 g can be written as… 3 x 10 8 g Ex II: 1,007,000,000 sec can be written as… 1.007 x 10 9 sec Ex III: 0.000 000 000 004 76 mL can be written as… 4.76 x 10 -12 mL

7. Significant Figures Atlantic - Pacific Rule: Decimal Present: Count from the Pacific side Decimal Absent: Count from the Atlantic side Start counting at the first non-zero number and count until you reach the end of the number Ex. I: 3.00700 Decimal Present… Pacific (left)… 6 sig. figs. Ex. II: 300,700 Decimal Absent… Atlantic (right)… 4 sig. figs.

8. Before we take this trip, let’s review significant figures… 1)0.0034050 L ___________ 2)33.600 m___________ 3)7500.0 g___________ 4)47,900 mm___________ 5)7,000,000,001 miles ___________ 6)8.07 Hz___________ Determine how many significant figures are in each of the following measurements. 5 5 5 3 10 3

9. More practice… 7)366.2 L ___________ 8)9,047,022 mg ___________ 9)12.76 g___________ 10) 999.9 J___________ Round the following measurements off so that they each contain 3 significant figures. 366 L 9,050,000 mg 12.8 g 1.00 x 10 3 J Notice this one must be in scientific notation to have 3 sig. figs.

10. Significant Figures in Calculations When multiplying and dividing, limit and round to the least number of significant figures in any of the factors. Example: 23.0 x 432 x 19 = 188,784 = 190,000 The answer is expressed as 190,000 or 1.9 x 10 5 since 19 has only two sig. figs.

11. Significant Figures in Calculations When adding and subtracting, limit and round your answer to the least number of decimal places in any of the numbers involved in the calculation. Example: 123.25 + 46.0 +86.257 = 255.507 = 255.5 The answer is expressed as 255.5 since 46.0 has only one decimal place.

12. Before we take this trip, let’s review significant figures… 11)36.57 m / 3.21 s = ___________ 12)41.376g + 13.3g + 42.9g=___________ 13)5.67 m x 13.44 m___________ 14)(5.83 m/ 2.67 s) /2.1 s___________ 15)9.374 V x 6___________ Perform the prescribed operations. Round your answers to the proper # of sig. figs. 11.4 m/s 97.6 g 76.2 m 2 1.0 m/s 2 60 V From now on, we will round all our answers to the correct # of significant figures.

13. Let’s say you want to travel from Oracle Jct to Casa Grande... You must travel through Tucson… a two part trip. Now back to our road trip…

14. Rule: You must stay on the roads

15. X

16. Rule: You need a map. Sometimes the map can be in your head. But, not at first.

17. OK…Lets talk about making maps and solving conversion problems. The method we use is called the “Factor-Label” method, a.k.a. dimensional analysis.

18. gallons kildurkins For Example: Given 1 kildurkin = 18 gallons This is our map.

19. gallons kildurkins For Example: Given 1 kildurkin = 18 gallons How many kildurkins is 14 gallons? 1 kildurkins 18 gallons 14 gallons =0.78 kildurkins

20. General Format... going to coming from given

21. gallons kildurkins Also given: 2 farkins = 1 kildurkin farkins Let’s expand the map...

22. gallons kildurkins Also given: 1 hogshead = 63 gallons farkins hogshead 1 barrel = 3.3 bushels bushel barrel 1 bushel = 8 gallons

23. gallons kildurkins farkins hogshead bushel barrel Now, Lets solve a problem. How many hogsheads are 14 barrels? Given: Start Here Finish Here The trip will require 3 transitions 1 2 3

24. gallons hogshead bushel barrel How many hogsheads are 14 barrels? 1 2 3 Given 14 barrels3.3 bushels 1 barrel 8 gallons 1 bushel 1 hogshead 63 gallons = 5.9 hogsheads

25. gallons kildurkins farkins hogshead bushel barrel Now you try one. How many farkins is 3.00 bushels? Start Here End Here This will require 3 Conversions.

26. bushelsgallonskildurkins farkins 3.00 bushels 8 gallons 1 bushel 1 kildurkin 18 gallons 2 farkins 1 kildurkin = 2.67 farkins

27. Wow! How Cool Is That!