Presentation on theme: "Significant figures. Significant figures: Are the numbers in a measurement that include all of the digits that are known, plus the last digit that is."— Presentation transcript:
Significant figures: Are the numbers in a measurement that include all of the digits that are known, plus the last digit that is estimated.
Calculating can change the # of significant digits. The following rules will help you determine how many significant figures a reported measurement has.
Rule #1 Every non zero number is assumed to be significant.
Rule 5 (an exception to rule 4) Numbers that are to the right of a non zero number where there is no decimal present are not significant. Unless it is stated that the measurement is known precisely.
Examples: 5000 = 1 significant digits = 4 significant digits = 6 significant digits (The zero between the 1 and the decimal is significant because it is between the significant zero’s after the decimal.)
Rule 6 You have an unlimited number of significant figs if you : A.Come up with the number by counting every thing. B. Are getting the number by converting within a system of measurement.
Examples: I counted = 5 significant digits There are 1000 meter in 1 Km = 4 significant digits There are 3600 seconds in 1 hour= 4 significant digits
Calculating Significant Digits When multiplying or dividing measurements, the final answer can not have more sig digs than the measurement with the smallest # of significant digs.
Example: 50.0 grams x 3.0 = grams \ 8.3 = 6.0
Calculating Adding and Subtracting When adding and subtracting, the answer must have the same number of decimal places as the number with the least number of decimal places.