1. Daily Review
Tell the difference between accuracy and precision. Give an example.
Record 56, in scientific notation.
Record in scientific notation.
What is the formula for percent error?

2. Significant Figures and Metric units
Chapter 3

3. Learning Objectives You will need to be able to:
Determine the number of significant figures in a number.
Calculate using significant figures
Round using significant figures

4. Significant Figures
In a measurement the last digit is considered to be an estimate (guess).
Significant figures in a measurement include those numbers that are known plus one estimates digit.

5. Significant Figure Rules
1) ALL non-zero numbers (1,2,3,4,5,6,7,8,9) are ALWAYS significant.
EX: has 5 Sig. Figs.
2) ALL zeroes between non-zero numbers are ALWAYS significant. “Captured Zeros”
EX 1.02 has 3 Sig. Figs.
3) ALL zeroes which are SIMULTANEOUSLY to the right of the decimal point AND at the end of the number are ALWAYS significant. “Place Holders”
EX: has 2 Sig. Figs.
EX: 100 has 1 Sig. Fig.
4) ALL zeroes which are to the left of a written decimal point and are in a number >= 10 are ALWAYS significant. “Trailing Zeros”
EX: has 4 Sig. Figs.

6. Practice: Sig. Figs.
Determine the number of significant digits in each of the following:
6.571 g
b) kg
c) 28.0 ml
d) 2500
e) g
Answers 4 5 3 2 6

7. Ten-Two In your notebook:
Take two minutes to summarize what you have learned to far!

8. Significant Figures: Rules for Calculation
Rule #1:ADDITION AND SUBTRACTION:
When adding or subtracting numbers, count the NUMBER OF DECIMAL PLACES to determine the number of significant figures. Record your answer using the FEWEST NUMBER of decimal places
(6 places after the decimal)
(4 places after the decimal)
(2 places after the decimal)
(on calculator)
Answer: (rounded to 2 places in the answer)

9. Significant Figures: Rules for Calculation
Rule #2 MULTIPLICATION AND DIVISION:
When multiplying or dividing numbers, count the NUMBER OF SIGNIFICANT FIGURES. Record your answer using the SMALLEST number of significant figures
(8 significant figures)
x (5 significant figures
(on calculator)
Answer (rounded to 5 significant figures)

10. Practice: Sig. Figs.
Using the rules for Significant figures calculate the following and record using the correct significant figures.
3.15 x 2.5 x 4.00
40.8 / 5.05
Answers 21
7.3 32
8.08

11. Measurement Activity

12. Sigs. Figs Daily Review What are significant figures?
Why are significant figures important?
How many significant figures are in the number ? ?
Calculate using the correct number of significant figures.
2.3 x 1.23
Sigs. Figs

13. Learning objectives You will need to be able to:
Understand the SI base units and their abbreviations
Use prefixes and convert between metric units
Understand measurement abbreviations.

14. Early Measurement
What do you find right or wrong with these forms of measurements?

15. The International System of Units

16. Prefixes for the SI System

17. Practice What is the unit of measurement for length?
What is the unit of measurement for count or quantity of a substance?
What is the base unit for temperature?
What is the base unit for mass?
Meter
Mole
Kelvin
Kilogram

18. Practice Give the abbreviation for the following measurement units:
centiliter
Millimeter
Megagram
picosecond
deciliter
Answers cL mm Mg ps dL

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

20. Practice: Metric conversions
Convert these using the diagram
1000 mg = _______ g
1 L = _______ mL
160 cm = _______ mm
14 km = _______ m
109 g = _______ kg
250 m = _______ km

21. Thinking log On a post-it note:
The hardest part of the lesson was_______________
I was successful in ___________________