1. Measurement Lab 2 Significant Figures Calculations

2. Objectives: Informal Assessment: Formal Assessment:
Use proper technique to make accurate and precise measurements.
Apply the rules for significant figures to calculations.
Informal Assessment:
Monitoring student interactions and questions as they complete the measurement lab and significant figures practice
Formal Assessment:
Analyzing student responses to measurement lab and significant figures practice
Common Core Connection
Use appropriate tools strategically
Attend to precision
Make sense of problem and persevere in solving them

3. Lesson Sequence Evaluate: Warm-Up
Explain: Measuring to the Correct Sig Figs
Elaborate: Measurement Lab Trial 2
Evaluate: Significant Figures Inquiry
Elaborate: Significant Figures Practice
Explain: Significant Figures Calculations
Elaborate: Significant Figures Calculation Practice
Evaluate: Exit Ticket

4. Warm - Up
What techniques can be used in lab to ensure that you are taking accurate and precise measurements?
How many decimal points can a ruler be measured to?

5. Objectives: Today I will be able to:
Use proper technique to make accurate and precise measurements.
Apply the rules for significant figures to calculations.

6. Homework Finish Significant Figures Calculations WS
Study for Significant Figures Quiz on Thursday, September 11
Collect Data for STEM Fair

7. Agenda Warm-Up Measuring to the Correct Sig Figs
Measurement Lab Trial 2
Significant Figures Inquiry
Significant Figures Practice
Significant Figures Calculations
Significant Figures Calculation Practice
Exit Ticket

8. Draw this table on the back of your measurement lab
Lab Equipment
Unit of Measurement
Number of Decimal Places it Can be Read to
Ruler/ Meter Stick
Balance
Beaker
Graduated Cylinder
Erlenmeyer Flask
Complete the table as Ms. Ose explains how to take measurements using the correct number of significant figures

9. Measurement Lab Trial 2
Travel to the stations in the lab and measure the mass, volume or length to the correct number of decimal places Record the number of sig figs in your trial 2 measurement. Record your answers on the poster on the board

10. Class Discussion
How do the trial 2 measurements differ from the trial 1 measurements?
Why are significant figures important?

11. Take out the Sig Fig Inquiry Worksheet
Class review of Significant Figure Rules

12. Significant Figure Practice
Complete the practice at your desk.
Answers will be reviewed as a class

13. Significant Figure Notes

14. What’s the SIGnificance?

15. How many decimals can each ruler be read to?

16. What volume of water is in the graduated cylinder?

17. Which balance do you think costs the most and why?

18. Significant Figure Calculations

19. Atlantic Pacific Rule

20. Atlantic Pacific Rule
If a decimal point is Present as in km, count from the “Pacific Side” from the first nonzero digit to the end. Meaning, count from the left side of the number
has 3 sig figs
- How many sig figs in
- There are 5 sig figs (start counting at 9)

21. Atlantic Pacific Rule
If the decimal point is Absent, as in g, count from the Atlantic Side beginning with the first nonzero digit and going to the end, counting any zero as significant. This means start from the right
g has 3 sig figs
How many sig figs in 190,542,100ml
- There are 7 sig figs

22. Examples m
- 5 kg
- 6
25,000,000, 000 mm
- 2
1,908,150 L
- 6
520 ml
- 2
.0102 ns
- 3

23. Sig Fig Calculations
You cannot be more precise than your least precise measurement
In multiplication and division, the measurement with the smallest number of sig digits determines how many digits are allowed in the final answer
If you have several steps, carry the extra digits. Only the final answer is rounded

24. Examples 6.15 m x 4.026 m = ? - 6.15 m has 3 sig figs
- Your answer can only have 3 sig figs
m2  24.8 m2

25. Examples .03287 g x 45.2 g = ? - .03287 g has 4 sig figs
- Your answer can only have three sig figs
g  1.49 g

26. Final Note
When doing calculations with significant figures, conversion factors do not figure in
Counts and defined numbers are EXACT and have no uncertain digits
Example: if you say there are 6 people in your family it is a counted number and is considered certain. There are not 6.1 people in your family
Example: 12 inches = 1 foot is defined – do not use significant figures. 1 foot will never be inches. In both cases, significant figures do not apply

27. Significant Figures Calculation Practice
Complete the practice at your desk. Problems not completed in class will become your homework.

28. Exit Ticket
Complete the calculation to the correct number of sig figs.
4.21 X =
– 2.2 =
Icebreaker:
Would you rather have legs as long as your fingers or fingers as long as your legs?
Would you rather win the lottery or live twice as long?