3.3 Significant Figures

Question 1

Significant Figures (SF)

Answer 1

All of the digits that can be known with certainty in a measurement PLUS an estimated last digit
-provide a system to keep track of the limits of a measurement

Question 2

4 Rules for Determining the Number of SFs

Answer 2

1. All non-zero digits are significant.
2. All zeros between non-zero digits are significant.
3. All beginning zeros are not significant.
4. Ending zeros are significant if the decimal point is written in.

Question 3

The choice of measuring instrument determines…

Answer 3

both the units and the number of significant figures.

Question 4

If you see a zero…

Answer 4

WRITE IT DOWN.

Question 5

The results of mathematical operations on measurements…

Answer 5

must reflect the number of significant figures in the original measurements.

Question 6

Addition and Subtraction Rule

Answer 6

The answer must not have any digits further to the right than the shortest addend.
(The answer should have as many decimal places as the addend with the smallest number of decimal places.)

Question 7

Multiplication and Division Rule

Answer 7

The answer for a multiplication and division operation must have the same number of significant figures as the factor with the least number of significant figures.

Question 8

100.

Answer 8

The decimal in written in to show that the last 2 zeros are important. Therefore, with the decimal included, this number has 3 significant figures.