1. KWL CHART WHAT DO YOU WANT TO KNOW? WHAT HAVE YOU LEARNED TODAY?
WHAT DO YOU KNOW ABOUT THE TERMS “ACCURACY” AND “PRECISION”?
WHAT DO YOU WANT TO KNOW?
WHAT HAVE YOU LEARNED TODAY?

2. KWL STRATEGY
K (what do you know W (what do L (what About Measurement) you want to have you know learned) about Measurement

3. CH. 2 Precision & Accuracy , % error, Metrics, Measurement & Significant Figures

4. Precision vs. Accuracy
In the context of the scientific method, precision and accuracy have two distinctly different meanings.
The accuracy of a measurement system is the degree of closeness of measurements of a quantity to its actual (true)value.
The precision of a measurement system is the degree to which repeated measurements under unchanged conditions show the same results.
See dartboard (p. 44)
A measurement system can be accurate but not precise, precise but not accurate, neither, or both.

5. Visualizing the concept

6. CALCULATING % ERROR
% error = measured – accepted accepted X 100 p. 45 #1 practice problem Find the % error if a mass measurement is 17.7 grams when the correct mass is 21.2 grams.

7. Example 2
A liquid’s volume is measured in a beaker as 40 mL. It is then measured in a graduated cylinder as 45.5 mL. Find the % error.

8. P. 45 # 1—2

9. p. 60 #35—37

10. MEASUREMENT WARM UP
1. Based on the following data collected, comment on this person’s accuracy & precision:
***Volume in beaker trial 1= 30.0 mL
Trial 2 = 31.0
Trial 3= 31. 5
***Volume in cylinder = mL
2. Calculate % error:
A student measures mass as 50.9 grams The instructor measures 55.9 grams.

11. WRITING ACTIVITY--ACTIVATOR
Write a paragraph to your friend explaining to him or her the difference between accuracy vs. precision. Include an example using the dartboard analogy. (refer to p. 44 if needed)

12. IPAD ACTIVITY—Introduction to Metrics
ecial_features/ext/internet_activities/ matovina/metric ONLY COMPLETE 1—6 and #8 TODAY USE YOUR OWN NOTEBOOK PAPER

13. ACTIVATOR:
Why is the metric system of measurement (which uses meters, liters, grams, etc.) preferred AND easier to use rather than the English system of measurement (which uses pounds, feet, etc.)?

14. ENGLISH SYSTEM UNITS: 1 foot. = 12 inches 1 pound = 16 ounces
1 cup = 8 ounces
1 yard = 3 feet
1 mile = 5280 feet

15. METRIC SYSTEM
Also known as the SI based system (International System of Measurements)
It is more preferred rather than the English system of measurements because it is based on units of 10.
Measurement systems are all based on “standards” which are physical representations for each measurement unit.
We will learn about the prefixes “Tera” through “pico”. (see chart)

17. METRIC QUANTITIES AND WHAT UNITS THEY ARE MEASURED IN: (see p
METRIC QUANTITIES AND WHAT UNITS THEY ARE MEASURED IN: (see p. 34 in your textbook)
Mass = gram Distance = meter Volume = liters or cubic meter Time = seconds Temperature = Kelvin Amount of a substance = mole Electric current = ampere Light intensity = candela Area = square meter Energy = joule

18. ADDING PREFIXES TO BASE UNITS
1 KILOmeter = ________________meters
1 CENTIgram = ______________________grams
1 millisecond = __________________seconds

20. THE METRIC LINE(STAIRCASE)

21. METRIC ACRONYM THE GREAT MIGHTY king henry died by drinking chocolate
milk
maybe
not
pasteurized

22. TELL WHAT EACH SYMBOL STANDS FOR:
mg kL Mm mm um m

23. METRIC CONVERSIONS

26. ACTIVATOR:
Name 3 basic metric units. Name 2 prefixes AND give their symbol. Name 1 thing you know about a “standard” of measurement.

27. 3 ways for measuring volume:
1. liquids—graduated cylinder (measures in mL)
2. rectangular shaped solids- use a ruler for
length x width x height (measured in cubic cm or cm3 or cc)
Irregular shaped solids—water displacement
***VOLUME—the amount of space something takes up

31. YOU TRY:
25 mL = ___________________cc (cm3) 25 cc = ________________________L

32. SUMMARIZER:
Describe how you would take the volume of a glass of water, a rectangular block, and a marble. Also, tell what units that you would use to measure each.

34. WRITING ASSIGNMENT:
(1-2 paragraphs)
Discuss the differences between area & volume. Include in your discussion: ways they are measured, units which they are measured in, and tools used to measure them. Also, remember the different methods for measuring volume.

35. Warm up % ERROR/METRICS
1. A lab tech measures the boiling point of water to be 99.5 C. The true boiling pt of water is C. Calculate the % error. (SHOW WORK!!)
g = ______________________ng
kg = ____________________Mg
daL = _______________________mL
L = __________________cm3

36. ACTIVATOR
In a paragraph, describe how mass, volume, length, and temperature are measured.

37. LAB—UNCERTAINTY OF MEASUREMENT
PART III #8 SHOW WORK FOR % ERROR Accepted values: Bottle = grams Clamp = grams Domino = grams Stopper = grams

38. METRIC WARMUP
GIVE THE SYMBOL FOR EACH UNIT:
1. Micrometer 4. Megameter
2. Meter millimeter
3. Kiloliter
WHAT QUANTITY DO THESE UNITS MEASURE?
7. meter gram
8. cc Cm3
9. liter Square meter
PERFORM THESE METRIC CONVERSIONS:
ng = _______________pg
m = ______________Mm
cc =_______________mL
L = __________________cm3

39. CONVERSIONS INVOLVING EXPONENTS
This is done when BOTH units have the SAME exponent (squared to squared or cubed to cubed)
Ex: 100 cm2 = _______________m2
cm to m is normally 2 spaces left, so multiply this 2 spaces x the exponent of 2 = total of 4 spaces left
Ex: Mm3 = ________________km3
Mm to km is normally 3 spaces right, so multiply by exponent of 3 = 9 spaces right

40. FINAL METRIC WARMUP 1. 55 cc = ______L 2. 0.00035 Mm = _________m
dL =____________kL
4. What do millimeters measure?
5. What do kilograms measure?
6. What do liters measure?
7. What do cubic millimeters measure?
8. What do square centimeters measure?
9. Which is larger: cc or 0.5 L?
10. Find the area of a box measuring 5 cm by 8 cm.
11. Does milli make the base unit larger or smaller?
12. Find the volume of a rock that’s dropped in 25 mL of water and the level then rises to 38 mL.

43. BOOK PROBLEMS (% error, metrics, accuracy/precision)
p. 59 #1, 4, 7, 8 ab, 9 ab, 16, 20, 21, 24, 25, 37
p. 63 #1, 3, 4, 6, 7, 8

44. ACTIVATOR
Explain why error always exists in measurement.

45. Significant Figures
Significant figures help scientists be able to do the same thing when taking measurements and doing calculations.
SEE P. 46

46. Sig Fig Rules Digits from 1-9 are always significant.
Zeros between two other significant digits are always significant
Final zeros to the right of the decimal place are significant.
Zeros used solely for spacing the decimal point (placeholders) are not significant (Unless specifically measured and noted with a line above the number).

47. HOW TO DETERMINE THE NUMBER OF SIG FIGS---p. 47
The letters "A" (decimal absent) and "P" (decimal present) correspond to the "Atlantic" and "Pacific" Oceans on a map. 

48. Now, imagine an arrow being drawn from the appropriate coast
Now, imagine an arrow being drawn from the appropriate coast.  Once the arrow hits a NONZERO digit, this digit and all of the digits after it are significant.

49. Decimal Absent
Example 1.  How many significant digits are shown in the number ?  Well, there is no decimal, so we think of "A" for "Absent".  This means that we imagine an arrow coming in from the Atlantic ocean
 this shows 3 significant numbers
as you do not count numbers until you hit a significant digit
Modified from

50. Decimal Present
Example 2.  How many significant digits are shown in the number ?  Well, there is a decimal, so we think of "P" for "Present".  This means that we imagine an arrow coming in from the Pacific ocean.
 This shows that the number has two significant digits after the non zero number is encountered
Modified from

51. NOW YOU TRY……. First decide if A or P?? HOW MANY SIG FIGS IN EACH?L
sec
,060 kg
moles
Kelvin Mm

52. TELL IF THE FOLLOWING ARE “ATLANTIC” OR “PACIFIC” AND THEN TELL HOW MANY SIG FIGS:
cm mg
g cm
m g
mm nm
kg km
Mm sec

53. HOW TO MAKE ZEROS SIGNIFICANT WHEN THEY’RE NOT ALREADY
You may ONLY do this to zeros in ATLANTIC numbers
put a bar over the zero
2500—has 2 sig figs
How to make 3 sig figs??
How to make 4 sig figs??
Put a decimal at the end (making it a pacific #)
2500
2500.

54. Problems involving Lines over zeros—1st decide if A or P??
TELL HOW MANY SIG FIGS IN EACH:
(1ST DECIDE IF A or P)
g g
g m
3. 28,007 L L
m cm
g m
6. 23,000 cm L
7. 28, 875 mm mm
8. 505,100 g ,650 Mm
L g

56. ROUNDING TO A CERTAIN NUMBER OF SIG FIGS
When trying to do this, move through the number from left to right. Ex: Round to 1 sig fig:

57. Round to 2 sig figs:
2895
0.0956
Round to 3 sig figs:
0.6

58. WARM UP TELL HOW MANY SIG FIGS ARE IN EACH--1st decide if A or P:
ROUND EACH TO 2 SIG FIGS:
ROUND EACH TO 1 SIG FIG:

60. Add/Substract with Sig Figs
Round answer to the FEWEST DECIMAL PLACES that are in the problem
g 4 mL cm
g mL cm

61. = round to 2 dec. = g
= round to 0 dec. = 1 mL
= round to 2 dec. = 8.73 cm

62. Multiply/Divide with Sig Figs
Round answer to the FEWEST SIG FIGS that are in the problem
2.32 cm x cm =
62.0 g / mL =
1.805 m x 6.0 m =

63. =round to 3 sig figs = 181 cm2
=round to 3 sig figs = g/mL
= round to 2 sig figs = 11m2

64. SUMMARIZER
Give any 3 measurements and tell how many sig figs are in each.
Describe the 2 different ways to round (add/subtract VS. Multiply/divide)
Name 1 way to make zeros significant when they’re not to begin with.

65. HOMEWORK—SIG FIGS HANDOUT
1—34 EVEN

66. WARM UP
m X m=
g g =
g / L =
g / L =
cm cm =

67. P. 50 #1—3
P. 57 #3—4

69. ACTIVATOR
Why would someone want to put a measurement into scientific notation?

70. Reduces the number of zeros in really big or really small numbers

71. SCIENTIFIC NOTATION
The number in front determines the number of sig figs
Starting out, the decimal MUST be written to the right of the first nonzero number in order to be in correct scientific form; then, depending on the exponent, it can be moved left or right to convert to a regular number.
5.64 x (correct form with 3 sig figs)
x (incorrect form) Why??
340 x (incorrect form) Why??

72. Other examples of Correct Form
6.023 x  4 sig figs
6.67 x  3 sig figs
2.00 x 10-3  3 sig figs

73. In your calculator, 3.05 x 109 may appear:
3.05 EE 9

74. Converting from Scientific Notation to Regular Number (Standard Form)
If the exponent is POSITIVE, move decimal that many places to the RIGHT.
Ex: x 103
***Remember to keep SIG FIGS the same!!
If the exponent is NEGATIVE, move decimal that many places to the LEFT.
Ex: x 10-3

75. YOU TRY:
x 105 =
x 10-3 =
x 100 =

76. CONVERTING INTO SCIENTIFIC NOTATION:
Remember that the decimal must be moved to the right of the first nonzero digit. Also, remember to keep SIG FIGS the same.
If the number is greater than 1 to start with, use a positive exponent.
Ex: 305,000
If the number is less than 1 to start with, use a negative exponent.
Ex:

77. YOU TRY:
,000. = = =

78. SIG FIGS/SCIENTIFIC NOTATION HANDOUT
SIG FIGS---EVEN (OPTIONAL)
SCIENTIFIC NOTATION--EVEN

79. WARM UP
PUT INTO SCIENTIFIC NOTATION:
PUT INTO STANDARD FORM (REGULAR NUMBER)
X 102
X 10-3

80. P. 57 #6
P. 60 #43—45

81. Accuracy, Metric, and Sig Figs
p. 48 #1-2
p #1-3
p. 60 #29, 38
p #2
p. 42 #1-3
p. 59 #6-9, 16, 20, 21, 23, 25a, 38, 50, 51

82. WHAT TO STUDY FOR MEASUREMENT TEST
1. Qualitative vs. quantitative measurement
2. What’s the purpose of a standard in measurement
3. Basic units for length, time, volume, mass, and temp.
4. Metric prefix symbols, numerical meanings, and exponent meanings
5. Metric conversions (normal, cc = mL, and exponent ones)
6. Units for area and volume
7. 3 ways to measure volume
8. % error
9. Accuracy vs. precision
10. Mass vs. weight
11. Counting # of sig figs AND calculation rules for sig figs
12. Scientific notation into standard form (and vice-versa)
13. Vocabulary sheet
14. Reading metric tools
15. Measurement video ?s