1. SIGNIFICANT FIGURES

2. What are SIG FIG’S Digits that carry meaning contributing to its precision. They help make our “precision” more accurate Precision-the degree to which repeated measurements under unchanged conditions show the same results.

3. HOW DO WE KNOW? 5 Simple Rules

4. Rule #1 All non-zeroes are significant Ex: 123 has 3 sig figs 4789 has 4 sig figs 2 has 1 sig fig

5. RULE # 2 All zeroes between non-zeroes are significant. Examples: 70002 (5 sig figs) 7000200 (5 sig figs) 205 (3 sig figs)

6. RULE # 3 All zeroes to the left of a decimal AND to the right of a non-zero are significant. Example: 7000200. (7 sig figs) 7000200 ( 5 sig figs) 120. (3 sig figs) 120 (2 sig figs)

7. RULE # 4 All zeroes to the RIGHT of a decimal point AND to the right of a non-zero are significant. Examples: 7000200.0 (8 sig figs) 702.05 (5 sig figs)

8. Rule 5 All zeroes to the left of a non-zero are not significant. Examples: 0.00000072 ( 2 sig figs) 10.00000072 ( 10 sig figs)

9. CONFUSED? Try the following problems for practice in your notes. Tell me how many sig figs there are and which rule or rules supports your answer.

10. PRACTICE PROBLEMS A.) 6.571 B.) 0.157 C.) 28.0 D.) 30.07 E.) 0.106 F.) 0.0067 G.) 26.509