1. No decimal: Everything EXCEPT 0’s at the end (4100  2 sig. fig.’s) Decimal: Everything EXCEPT 0’s at the beginning (0.0032  2 sig. fig.’s) (1000.  4 sig. fig.’s) (1.0003  5 sig. fig.’s)

2. If the number is in Scientific notation: Everything before the x 10 something (1.540 x 10 17  4 sig. fig.’s) (1.2 x 10 24  2 sig. fig.’s)

3. Count the sig. fig.’s: 1. 200 2. 200. 3. 200.00 4. 2.000 x 10 14 5. 200.01 6. 0.000007 1 5 4 5 3 1

4.  Line up the decimal places  Draw a straight line just past the last digit they have in common.  Add/subtract  Keep everything to the left of the line.

5. 23.2 6.052 + 139.4 23.2 6.052 + 139.4 168.652 168.7 153 600 + 168 921 900 0.0097 + 0.0563 0.0660

6.  Round the answer to the same number of sig figs as in the number with the fewest sig figs. 23.2 x 0.1257 = 2.91642 2.92 14.89 ÷ 0.003 = 4963.333 5000

7. 42.7 X 0.0046 = 0.19642 0.20 407.1 / 12.3 = 33.09756 33.1 2.7 X 0.1400 = 0.378 0.38

8.  Found by: Counting (ex: I see 24 students in my class) By definition (there are 12 inches in a foot or 1000 m in 1 km)  Do not take in account any exact numbers when counting sig figs during calculations. *so if you are dividing #cm/#pages, the #pages is exact so your final answer will have the same number of sig figs as your # cm.