1. Warmup 9/21/15 How many millimeters are in a kilometer? What other conversions between units do you know? Objective Tonight’s Homework To refresh on how to convert metric units Finish conversion worksheet

2. The Metric System Today we’re going to start discussing chemistry. We’re going to begin with units. In chemistry, we often need be careful with measurement because we’re often dealing with very precise things. So to start, let’s take notes of the different metric prefixes and how big or small each one means.

3. Notes on Metric Conversion We attach prefixes – a group of letters – in front of each metric unit to tell us how much bigger or smaller we want it. prefixlettersize - megaM 1,000,000 - - kilok 1,000 - hectoh 100 - dekada10 - “normal”-1 - decid0.1 - centic0.01 - millim0.001 - - microμ0.000 001

4. Notes on Metric Conversion To convert units, we have a simple trick. - If we’re converting to something bigger, we move the decimal to the left. (Divide) - If we’re converting to something smaller, we move the decimal to the right. (Multiply) The letter after each prefix tells us what we’re measuring. m = metersL = litersg = grams Example: Convert 28 mm to km. We want to go up the table, so we need to move our decimal left. We’re going up 6 steps, so we move our decimal left 6. 28 mm  0.000028 km

5. Practice with Metric Conversion 1. 1000 cl = ____ L 2. 120 mm = ____ cm3. 1200 cl = ____ L 4. 2 cm = ____ mm 5. 11000 L = ____ kL6. 10 cl = ____mL 7. 12000 m = ____ km 8. 8 g = ____ cg9. 80 ml = ____ cL 10. 3 L = ____ cL 11. 2000 L = ____ kL12. 5 cm = ___ mm 13. 900 cm = ____ m 14. 11 cg = ____ μg15. 900 m = __ km 16. 7000 ml = ____ L 17. 5 kg = ____ g18. 60 mm = __ cm 19. 1 kg = ____ g 20. 4000 ml = ____ L21. 1 cl = ____ mL 22. 1100 L = ____hL 23. 10000000 g = __ Mg24. 20000 μl = __ L 25. 7000 L = ____ kL 26. 70 ml = ____ cL27. 5 g = ____ cg 28. 9 cl = ____ mL 29. 1 g = ____ cg30. 8 kg = ____ g

6. Exit Question How many dekameters are in a hectometer? a) 1 b) 10 c) 100 d) 1000 e) 0.1 f) None of the above