1. Accuracy vs. Precision
Accuracy is a description of how close a measurement is to the correct or accepted value of the quantity measured.
Ex: if the correct value is 5, then 4.95 is accurate. 2 is not accurate.

2. Accuracy vs. Precision
Precision is the degree of exactness of a measurement.
Ex: If you have three measurements: 5.10, 4.95, and 4.98, they are precise.
If a measurement is precise, it may not be accurate!

4. Significant Figures
Significant figures are a way to help keep track of imprecise measurements.
Significant figures are the digits that are known for certain, as well as the first digit that is uncertain.
Ex: cm has 3 significant figures. Two are known for certain, 0.2 is uncertain. It is uncertain because the digit after it is not known.

5. Significant Figures Rules for determining significant figures:
- All whole numbers (except for zero) are significant
Zeros between other nonzero digits are significant
Ex: has 3 significant figures
has five significant figures
Zeros in front of nonzero digits are NOT significant
Ex: has 3 significant figures
has 1 significant figure
Zeros that are at the end of a number and to the right of a decimal are significant.
- Ex: has four significant figures
2.000 has four significant figures