Metric System Basics

1. Metric System Basics

2. Metrics • Scientists are very lazy, they don’t want to have to remember all of those different conversions. • So instead we use the Système International (SI)Its French! • Or we can just say the Metric System. • Its all based on the number 10.

3. Metrics - Distance What is Distance? Definition: The space between two points. Tool: Meter Stick Ruler Unit: Meter (m)

4. Metrics - Volume What is Volume? Definition: The amount of space something takes up. Tool: Graduated Cylinder Ruler(Length x Width x Height) Unit: Liter (L)

5. Metrics - Mass What is Mass? Definition: The amount of stuff (or Matter) inside an object. Tool: Electric or Mechanical Balance Unit: Gram (g)

6. Metrics - Temperature What is Temperature? Tool: Thermometer. Definition: How fast the particles of an object are moving (due to heat). Unit: Degrees Celsius (oC)

7. Metrics - Temperature • So remember: • 0 o Celsius is when water freezes • 100 o Celsius is when water boils.

8. kilo- (K) 1000 hecto- (H) 100 deka- (D) 10 Liter (L) Meter (m) Gram (g) deci- (d) .1 centi- (c) .01 milli- (m) .001 Metrics – Powers of Ten

9. Metrics – Powers of Ten • As we change from different types of measurements, we change our prefix. • For example 30 millimeters = 3 centimeters • They are both measures of length, but a millimeter is ten times smaller than a centimeter. • Let’s practice a few conversions.

10. Converting Metrics Meter-m Liter-L Gram-g kilo 1000 hecto 100 deka 10 Base Unit K H deci 1/10 centi 1/100 Dk milli 1/1000 d c m

11. Converting Metrics To convert to a larger unit, move the decimal point to the left or divide:  kilo 1000 hecto 100 deka 10 Base Unit deci 1/10 centi 1/100 milli 1/1000 To convert to a smaller unit, move the decimal point to the right or multiply: 

12. Converting Metrics Convert 6 cm = _____ mm Convert 6 cm = 60 mm kilo 1000 hecto 100 deka 10 Base Unit deci 1/10 centi 1/100 milli 1/1000 • We are converting to: • larger unit • smaller unit

13. Converting Metrics Convert 40 mm = _____ cm Convert 40 mm = 4 cm kilo 1000 hecto 100 deka 10 Base Unit deci 1/10 centi 1/100 milli 1/1000 • We are converting to: • larger unit • smaller unit

14. Converting Metrics Convert 90 cm = _____ m Convert 90 cm = 0.9 m kilo 1000 hecto 100 deka 10 Base Unit deci 1/10 centi 1/100 milli 1/1000 • We are converting to: • larger unit • smaller unit

15. Converting Metrics Convert 200 mm = _____ m Convert 200 mm = 0.2 m kilo 1000 hecto 100 deka 10 Base Unit deci 1/10 centi 1/100 milli 1/1000 • We are converting to: • larger unit • smaller unit

16. Converting Metrics 1 1000 mg = _______________ g 1L = _______________mL 160 cm = _______________ mm 14 km = _______________Dm 109 g = _______________dg 240 m = _______________cm 1000 1600 1400 1090 24,000

17. Dimensional Analysis

18. What is Dimensional Analysis? • Dimensional analysis is a problem-solving method that uses the idea that any number or expression can be multiplied by one without changing its value. • It is used to go from one unit to another.

19. How Does Dimensional Analysis Work? • A conversion factor, or a fraction that is equal to one, is used, along with what you’re given, to determine what the new unit will be.

20. In chemistry, it is often useful to be able to convert from one unit of measure to another For example: mass of a substance converted to the number of atoms in that substance, or converting from one metric unit to another metric unit

21. First we will see how it works withdozen.

22. You know that a dozen is 12 of something. If you have 36 donuts, how many dozen donuts do you have?

23. Use this relationship to convert from individual donuts to dozen donuts: You want to know how many dozen in 36 donuts, and you know there is 1 dozen per 12 donuts, or 1 dozen 12 donuts

24. 1 dozen 12 donuts 36 donuts x In the problem how many dozen in 36 donuts, you know there is 1 dozen per 12 donuts, or 1 dozen Use this relationship to convert from individual donuts to dozen donuts: 12 donuts

25. In the problem how many dozen in 36 donuts, you know there is 1 dozen per 12 donuts, or 1 dozen Use this relationship to convert from individual donuts to dozen donuts: 12 donuts 1 dozen 12 donuts 36 donuts x 1 dozen 12 donuts 36 donuts x =

26. 36 dozen 12 = In the problem how many dozen in 36 donuts, you know there is 1 dozen per 12 donuts, or 1 dozen Use this relationship to convert from individual donuts to dozen donuts: 12 donuts 1 dozen 12 donuts 36 donuts x 1 dozen 12 donuts 36 donuts x =

27. 36 dozen 12 = 3 dozen = In the problem how many dozen in 36 donuts, you know there is 1 dozen per 12 donuts, or 1 dozen Use this relationship to convert from individual donuts to dozen donuts: 12 donuts 1 dozen 12 donuts 36 donuts x 1 dozen 12 donuts 36 donuts x =

28. 3 dozen = 36 donuts

29. there are 12 donuts in 1 dozen 12 donuts 2.5 dozen x 1 dozen If you have 2.5 dozen donuts, how many individual donuts are there?

30. 2.5 dozen x 12 donuts 1 dozen 2.5 x 12 donuts = 1 30 donuts = If you have 2.5 dozen donuts, how many individual donuts are there? 12 donuts 2.5 dozen x = 1 dozen

31. notice the two conversion factors are reciprocals of each other Here are the two problems side by side: 2

32. = 1 = 1 12 donuts 1 dozen 1 dozen 12 donuts 12 donuts = 1 dozen

33. converts donuts to dozen 12 donuts 1 dozen 1 dozen 12 donuts 12 donuts = 1 dozen = 1 = 1

34. converts dozen to donuts 12 donuts 1 dozen 1 dozen 12 donuts 12 donuts = 1 dozen = 1 = 1

35. Since conversion factors always equal 1, you can multiply them by anything you want and still end up with the same thing except that it will be in a different form

36. Let’s try converting donut mass to number of donuts…

37. If you have 9900 grams of donuts, how many donuts do you have if each donut has a mass of 150 grams?

38. If you have 9900 grams of donuts, how many donuts do you have if each donut has a mass of 150 grams? What’s the conversion?

39. If you have 9900 grams of donuts, how many donuts do you have if each donut has a mass of 150 grams? 1. what is the qestion asking you to convert?

40. If you have 9900 grams of donuts, how many donuts do you have if each donut has a mass of 150 grams? 1. what is the qestion asking you to convert? grams to donuts

41. If you have 9900 grams of donuts, how many donuts do you have if each donut has a mass of 150 grams? 2. what is the relationship between grams and donuts?

42. If you have 9900 grams of donuts, how many donuts do you have if each donut has a mass of 150 grams? 2. what is the relationship between grams and donuts? 150 grams = 1 donut

43. 3. set up the conversion factors:

44. 150 g 1 donut = 1 1 donut 150 g = 1 150 g = 1 donut so… and

45. 150 g 1 donut = 1 1 donut 150 g = 1 150 g = 1 donut these are your conversion factors

46. 150 g 1 donut = 1 1 donut 150 g = 1 150 g = 1 donut converts donuts to grams (grams on top)

47. 150 g 1 donut = 1 1 donut 150 g = 1 150 g = 1 donut converts grams to donuts (donuts on top)

48. The question is… If you have 9900 grams of donuts, how many donuts do you have if each donut has a mass of 150 grams?

49. begin with the amount given in the problem The question is… 9900 grams If you have 9900 grams of donuts, how many donuts do you have if each donut has a mass of 150 grams?

50. The question is… If you have 9900 grams of donuts, how many donuts do you have if each donut has a mass of 150 grams?