DO NOW
You must be silent and
working for credit
 Be on time
 Enter silently
 Grab papers
 Immediately start work
 No talking
Late work  bin
1. How many days left until
we meet our big goal?
2. If something is accurate,
the measurements are
close to
_____________.
3. Is the picture 
accurate, precise,
neither, or both?
4. Tomorrow is Friday.
What does that mean?
DO NOW REVIEW
1. How many days left until we meet our big goal?
2. If something is accurate, the measurements are
close to _____________.
3. Is the picture below accurate, precise, neither, or
both?
4. Tomorrow is Friday. What does that mean?
NOTES
 Notes Expectations:
Silent
Write what’s in red
Raise hand for questions related to content
No movement/bathroom during notes
 Key Point #1: SIGNIFICANT
FIGURES tell us the known digits in a
measurement
 So what did we find – which ruler gave us the most
significant figures? (the most known digits?)
Significant Figures
 RULE 1: All non-zero numbers are
significant.
 315
 3 sig figs
 542334
 6 sig figs
RULE #2:
Zeros are weird
and come in 3 flavors
FLAVOR 1: Leading Zeros
FLAVOR 2: Captive Zeros
FLAVOR 3: Trailing Zeros
RULE #2.1 (Leading Zeros):
These precede non-zero digits and
don’t count. They are only placeholders.
0.0023
2 sig figs
0.02300
4 sig figs
RULE #2.2 (Captive Zeros):
These are between nonzero digits.
They always count as sig figs.
1.009
4 sig figs
230,004
6 sig figs
RULE #2.3 (Trailing Zeros):
These are zeros at the right end of the
number. They are significant only if
the number has a decimal point.
100 =
1
sig fig
100. =
3 sig figs
Practice
INDEPENDENT PRACTICE – count the number of
significant figures in each of the numbers presented
Write on your own sheet (to turn in)
You do not need to write the number.
I will be grading for accuracy 
You have 7 minutes!
Work alone
Work silently
HUSTLE HARD!
INDEPENDENT PRACTICE
1)
2)
3)
4)
5)
6)
7)
72.3 _____
508.0 _____
706 _____
3140 _____
3059.008 _____
000.510 _____
0.00234 _____
8)
948030 _____
9)
10)
11)
12)
13)
14)
15)
6187. _____
45000 _____
2450098 _____
234005.0 _____
000.5065 _____
4560 _____
54432.0 _____
Exit Ticket
What’s due? Sig fig practice parts 1 and 2
1. What do significant figures tell us?
2. Tell me the number of significant figures in the
following problems:
a. 34500
b. 345.00
c. 0.00436
d. 50.003
Homework: Significant Figures Worksheet