1. Significant Figures
Box and Dot Method

2. Step 1
Draw a box around all nonzero digits, beginning with the leftmost nonzero digit and ending with the rightmost nonzero digit in the number.

3. Definitions
Trailing zeros- refers to any and all zeros present to the right of the rightmost nonzero digit.( i.e. to the right of the box drawn in STEP 1)
Leading zeros- refers to any and all zeros present to the left of the leftmost nonzero digit.( i.e. to the left of the box drawn in STEP 1)

4. Step 2
If dot (aka decimal point) is present, draw a box around any trailing zeros.

5. Step 3 Consider any and all boxed digits significant. 0.0123012300
How many significant digits?

6. ZEROS If there are captive zeros, they are significant figures.
Captive means that they are between 2 nonzero digits.
Example: 202 has 3 sigfigs
Example: has 7 sigfigs

7. ZEROS
If there is a decimal point at the end of the number all digits are significant, if there isn’t a decimal point at the end of the number only the nonzero digits are significant
Example: has 3 sigfigs, but
100 has only 1 sigfig (no decimal)

8. Significant Figures
Calculations

9. Multiplying and Dividing
The LEAST number of significant figures in any number of the problem determines the number of significant figures in the answer.
Multiply or divide
Round

10. Adding and Subtracting
Add or subtract
Round the answer to the LEAST number of places in the decimal portion of any number in the problem.
The least precise quantity has the fewest digits to the right of the decimal point.