1. Significant Figures Used to report all precisely known numbers + one estimated digit

2. Rule #1 Every nonzero digit is significant Every nonzero digit is significantExamples: 24 = 2 3.56 = 3 7 = 1

3. How many Significant Figures are in the number 3994 g. 1234567891011121314151617181920 21222324252627282930 1. 4 2. 5 3. 2 4. One million! 5. 0

4. Rule #2 Zeros between non-zeros are significant Zeros between non-zeros are significantExamples: 7003 = 4 40.9 = 3

5. Rule #3 Zeros appearing in front of non-zero digits are not significant Zeros appearing in front of non-zero digits are not significant Act as placeholders Act as placeholders Can’t be dropped, show magnitude Can’t be dropped, show magnitude Examples: Examples: 0.00024 = 2 0.453 = 3

6. How many sig figs in the number 0.00678 kg. 1234567891011121314151617181920 21222324252627282930 1. 5 2. 6 3. 3 4. infinite

7. Rule #4 Zeros at the end of a number and to the right of a decimal point are significant. Zeros at the end of a number and to the right of a decimal point are significant.Examples: 43.00 = 4 1.010 = 4 1.50 = 3

8. Rule #5 Zeros at the end of a number and to the left of a decimal point aren’t significant Zeros at the end of a number and to the left of a decimal point aren’t significantExamples: 300 = 1 27,300 = 3

9. How many sig figs is the following measurement 809 cm. 1234567891011121314151617181920 21222324252627282930 1. 1 2. 2 3. 3

10. Special Rule Always remember PA Always remember PA PA If a decimal point is present, start on the Pacific (P) side and begin counting at the first non-zero digit all the way to the end. If a decimal is absent, start on the Atlantic (A) side and begin counting at the first non-zero digit all the way to the end.

11. Special Rule (cont.) Remember PA Remember PAExamples: 123.003 = decimal present, start on “P” side, begin counting Answer = 6

12. Special Rule (cont.) Remember PA Remember PAExamples: 204,000 = decimal absent, start on “A” side, begin counting at first non- zero digit until you hit the end of the number. Answer = 3

13. How many sig figs are in the measurement 5600 km 1234567891011121314151617181920 21222324252627282930 1. 1 2. 2 3. 3 4. 4

14. Sig. Fig. Math Rules Addition / Subtraction: Addition / Subtraction: Answers can’t have more numbers to the right of the decimal point than the number in the problem with the least amt. of numbers to the right of the decimal point. Example = 24.1 + 3.35 + 2.23 Calculator says – 29.68 (wrong) Answer – 29.7

15. Choose the answer with correct # of sig figs 9.0 cm + 7.666 cm + 5.44 cm 1234567891011121314151617181920 21222324252627282930 1. 22.1 cm 2. 22 cm 3. 22.106 cm

16. Sig. Fig. Math Rules Multiplication / Division: Multiplication / Division: Your answer can’t have more sig. figs. than the number in the problem with the least amt. of sig. figs. Example = 60.56227892 x 35.25 Calculator says – 2134.890832 (wrong) Answer - 2135

17. Perform the following calculation 5.35 m x 0.4 m = 1234567891011121314151617181920 21222324252627282930 1. 2 m 2 2. 2.14 m 2 3. 2.1400 m 2 4. 2.140 m 2