1. Significant Figures
Any digit in a measurement that is known with certainty plus one final digit, which is somewhat uncertain or estimated.

2. Making Measurements with Sig Figs
Record every digit you know for certain, plus one that you estimate
On this graduated cylinder, we know the 10s place and the 1s place for certain (there are lines), so we will estimate the tenths place
The volume is 52.7 mL

3. All nonzero digits are significant
Rule # 1
All nonzero digits are significant
Example: 2.14 has 3 sig figs

4. Zeroes between nonzero digits are significant.
Rule # 2
Zeroes between nonzero digits are significant.
Example: 2001 has 4 sig figs

5. Trailing zeroes are significant ONLY if there is a decimal point.
Rule # 3
Trailing zeroes are significant ONLY if there is a decimal point.
Example:
4000 has 1 sig fig
4000. has 4 sig figs
has 5 sig figs

6. Rule # 4
Zeroes preceding the first nonzero digit in a number are NEVER significant.
Example: has 1 sig fig

7. How many sig figs?
227 cm L
700 s
2.50 x 1054 atoms

8. Rounding Rules Round up if the trailing number is 5 and above.
Rounded to 4 significant figures would be
Leave preceding digit the same if the trailing number is 4 and below.
Rounded to 4 significant figures would be

9. Round these to 3 sig figs!
2.457
2.453
9.900 x 10-5
300001

10. Sig Fig Addition/Subtraction Rule
Record your answer according to the number having the least number of decimal places (the least accurate)
Example: 2 cm cm = 14 cm

11. Sig Fig Multiplication/Division Rule
Record your answer according to the number having the least total number of significant figures
Exceptions: do not include constants (ex. pi, the number of sides a square has, etc.) in your determination of the number of sig figs
Example: 2.0 cm x 12.0 cm = 24 cm2

12. Accuracy
The extent to which a measurement approaches the true value of a quantity
Is this accurate?

13. Precision
The extent to which a series of measurements of the same quantity made in the same way agree with each other
Is this accurate, precise, neither, or both?