1. Significant Figures
Sig Figs

2. Sig Figs
Scientists use significant figures to show the precision of a measured quantity.
When you use measurements in calculations, the answer is only as precise as the least precise measurement used in the calculation
The measurement with the fewest significant figures.

3. Rules for Sig Figs Any non-zero number is ALWAYS significant.
Any zero between non-zero numbers is significant.
Any zero before a non-zero number is NOT significant.
Any zero after a non-zero number is significant ONLY IF there is a decimal in the number.

4. Any non-zero number is ALWAYS significant62
1219
2 sig figs
4 sig figs

5. Any zero between non-zero numbers is significant
803
3091
82,024
3 sig figs
4 sig figs
5 sig figs

6. Any zero before a non-zero number is NOT significant.
3 sig figs
0.0132
These are called leading zeros
3 sig figs
4 sig figs

7. 83,000 2 sig figs 83,000. 83.000 5 sig figs 5 sig figs
Any zero after a non-zero number is significant ONLY IF there is a decimal in the number.
83,000
83,000.
83.000
These are called trailing zeros
2 sig figs
(No Decimal)
5 sig figs
(Decimal)
5 sig figs
(Decimal)

8. 5 sig figs 10082 70,000 0.0025 1 sig fig 0.000309 50010.000 2 sig figs
Examples
10082
70,000
0.0025
5 sig figs
1 sig fig
2 sig figs
3 sig figs
8 sig figs
5 sig figs

9. Multiplying and Dividing (round to least number of sig figs)
Identify the sig figs for each number
Round answer to the least number of sig figs.
Look at the number next to last sig fig to determine rounding
62 ÷ 41 =
Answer: (2 sig figs)

10. Adding and Subtracting (Round to least precise)
Stack the numbers you are adding or subtracting. (line up the decimals)
Identify the sig figs for each number.
Round answer to the same number of decimal places as the number with the fewest decimal places.

11. 13.019 +1.2 14.2198 Answer: 14.2 Answer: 292 Example
Answer: 14.2
Answer: 292

12. Examples
62,881 ÷ 97
5,621 x 893
218 ÷ 26
59,411 x 2
307 x 32,000
8.00 ÷ 532
6 x 6
63.1 – 0.02 –
1.7 –
6 + 6