Transcript Measurement Lab 2 Significant Figures Calculations

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Objectives:
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Explain why significant figures are important to making
measurements.
Apply the rules for significant figures to calculations.
Apply the safety rules to a safety activity challenge.
• Informal Assessment:
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Monitoring student interactions and questions as they
complete the measurement lab and significant figures practice
• Formal Assessment:
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Analyzing student responses to measurement lab and
significant figures practice
• Common Core Connection
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Use appropriate tools strategically
Attend to precision
Make sense of problem and persevere in solving them
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Evaluate: Warm-Up
Explain: Significant Figure Notes
Elaborate: Significant Figures Calculation
Practice
Engage/Elaborate: Safety Activity Challenge
Evaluate: Exit Ticket
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Determine the number of significant figures
in the measured values below
◦ 5100
◦ 0.000720
◦ 41004
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What technique should be used when mixing
acid and water in a lab setting?
What protocol should be followed if a
chemical gets into your eye during lab?
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Today I will be able to:
• Explain why significant figures are important to making
measurements.
• Apply the rules for significant figures to calculations.
• Apply the safety rules to a safety activity challenge.
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
Finish Safety Challenge WS
Study for Significant Figures Quiz on Friday,
September 5
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Warm-Up
Significant Figures Notes
Significant Figures Calculations Practice
Safety Activity Challenge
Exit Ticket
•
If a decimal point is Present as in
52.3 km, count from the “Pacific
Side” from the first nonzero digit
to the end. Meaning, count from
the left side of the number
- 52.3 has 3 sig figs
- How many sig figs in .0093077
- There are 5 sig figs (start
counting at 9)
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If the decimal point is Absent, as in
1530 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
- 1530 g has 3 sig figs
How many sig figs in
190,542,100ml
- There are 7 sig figs
• .0026702
m
-5
• 19.0750 kg
-6
• 25,000,000,
000 mm
-2
• 1,908,150
-6
• 520 ml
-2
• .0102 ns
-3
L
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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
 6.15
m x 4.026 m = ?
- 6.15 m has 3 sig figs
- 4.026 m has 4 sig figs
- Your answer can only have 3 sig
figs
- 24.7599 m2  24.8 m2
• .03287
g x 45.2 g = ?
- .03287 g has 4 sig figs
- 45.2 g has 3 sig figs
- Your answer can only have three
sig figs
- 1.485724 g  1.49 g
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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
11.99 inches. In both cases, significant figures
do not apply
Complete the practice at your desk.
Work in your rows to complete the challenge

Complete the calculation to the correct
number of sig figs.
◦ 4.21
X
◦ 5.126
–
5.5270 =
2.2 =
Icebreaker:
◦ If you could turn yourself into something different
(car, animal, plant, etc) for one week, what would it
be?
◦ Would you rather be 4 inches tall or 100 ft tall?