SIGNIFICANT DIGITS

# SIGNIFICANT DIGITS

## SIGNIFICANT DIGITS

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##### Presentation Transcript

1. SIGNIFICANT DIGITS & Significant Zero Rules

2. SIGNIFICANT DIGITS: Represent numbers that are actually measured with some type of a measurement device.

3. SIGNIFICANT DIGITS • Sig Digs will include all certain digits plus ONEestimated digit. 5.632 g certain digits estimated digit

4. SIGNIFICANT DIGITS • certain digits: have calibrated markings on the instruments • estimated digits: between the 2 markings (if right on a marking, your est. is 0)

5. Uncertainty of last digit: …is assumed to be + or -1 unless other wise stated.

6. ROUNDING 1. If the decimal is greater than 0.5 round up 2. If the decimal is less than 0.5 round down 3. If the decimal is exactly 0.5 (ex: 20.5) round up

7. Reading an Instrument The more calibrated marks on the instruments, the more sig digs are in your measurement--the more accurate your measurement!

8. SIGNIFICANT DIGITS EXAMPLES 1 2 What would the measurement be?

9. SIGNIFICANT DIGITS EXAMPLES 4 5 What would the measurement be?

10. SIGNIFICANT DIGITS EXAMPLES How long is the green line?

11. SIGNIFICANT DIGITS EXAMPLES What would the measurement be?

12. SIGNIFICANT DIGITS EXAMPLES What would the measurement be?

13. Significant Figures – Rules 1. Every nonzero digit in a reported measurement is assumed to be significant. Example: 24.7 m, 0.743 m, and 714 m all have ___ sig figs.

14. Significant Figures – Rules 2. Captive zerosalways count as significant figures. Example: 7003 m, 40.79 m, and 1.503 m all have ___ sig figs.

15. Significant Figures – Rules 3. Leading zeros do NOT count as significant figures. Example: 0.0071 m, 0.000099 m, and 0.42 m all have ___ sig figs. *Scientific Notation…we’ll talk about this later

16. Significant Figures – Rules 4. Trailing zeros are significant only if the number contains a decimal point. Example: 43.00 m, 1.010 m, and 9.000 m all have ___ sig figs.

17. Significant Figures – Rules 5. Trailing zeros are NOT significant when there is not a decimal point Example: 200 m, 7000 m, and 10,000 m all have ___ sig fig.

18. WHICH ZEROES ARE SIGNIFICANT? 6.002 10.50 269.00 0.009 0.50 6.770 150

19. Unlimited Sig Figs! • Counting If you count 23 people in the room, there are exactly 23 people and the number has an infinite number of “understood” zeros behind it. • Exactly Defined Quantities Example: there are EXACTLY 60 minutes in 1 hour.

20. Sig Fig Practice How many significant figures in each of the following? 1.0070 m  5 sig figs 17.10 kg  4 sig figs 100,890 L  5 sig figs 3.29 x 103 s  3 sig figs 0.0054 cm  2 sig figs 3,200,000  2 sig figs