Unit1 part2
- 4. Significant digits Every nonzero digit in a reported measurement is assumed to be significant. Zeroes appearing between nonzero digits are significant.
- 5. Zero . . . Zeroes appearing in front of nonzero digits are not significant. They act as placeholders. 0.0000205
- 6. Zero . . . Zeroes appearing in front of nonzero digits are not significant. They act as placeholders. 0.0000205 or 2.05 x 10-5
- 7. Zero . . . Zeroes at the rightmost end of a measurement that lie to the left of an understood decimal point are not significant if they serve as placeholders to show the magnitude of the number. 20,500
- 8. Zero . . . Zeroes at the rightmost end of a measurement that lie to the left of an understood decimal point are not significant if they serve as placeholders to show the magnitude of the number. 20,500 or 2.05 x 10 4
- 9. Zero . . . Zeroes at the end of a number and to the right of a decimal point are always significant. 20.050 all digits are significant
- 10. Unlimited: There are two situations in which numbers have an unlimited number of significant figures: First: A number that is counted is exact. 25 books Second: exactly defined quantities such as those found within a system of measurement. 453.5 grams = 1 pound
- 11. Rounding ◦If the digit immediately to the right of the last significant digit is less than 5, it is simply dropped and the value of the last significant digit stays the same. ◦If the digit in question is 5 or greater, the value of the digit in the last significant place is increased by 1.
- 12. Addition and subtraction The answer to an addition or subtraction calculation should be rounded to the same number of decimal places (not digits) as the measurement with the least number of decimal places.
- 13. Addition and subtraction: 450.0 – 100.30 =
- 14. Addition and subtraction: 450.0 – 100.30 = 349.7
- 15. Addition and subtraction: 3.2936 + 2.178 + 0.01 + 1.09 =
- 16. Addition and subtraction: 3.2936 + 2.178 + 0.01 + 1.09 = 6.6
- 17. Multiplication and division: In calculations involving multiplication and division, you need to round the answer to the same number of significant figures as the measurement with the least number of significant figures.
- 18. Multiplication and division: 3.10 x 0.0020 = 1.002790
- 19. Multiplication and division: 3.10 x 0.0020 = 1.002790 0.0062
- 20. Can I get partial credit? Significant digits matter . . .