1.  How many steps are in the scientific method?  Why are sig figs important?  When are zeros significant?  How should we write our answers when using sig figs?

2. Mr. Schlamb

3.  All measured quantities have significant digits because they are approximated  The number of significant digits determines the precision of the measurement  The number of sig figs depends on the smallest unit on the measuring device

4.  The digit farthest to the right in a measurement is estimated  All nonzero digits are significant  https://www.youtube.com/watch?v=hQpQ0h xVNTg https://www.youtube.com/watch?v=hQpQ0h xVNTg

5. 1. Nonzero digits are significant 2. Final zeros after a decimal point are significant 3. Zeros between tow significant digits are significant 4. Zeros used only as placeholders are not significant

6.  How many sig figs do each of the following have? (answer on your own sheet of paper quietly). ◦ 5.0 ◦ 14.90 ◦ 0.0 ◦ 300.00 ◦ 5.06 ◦ 304 ◦ 0.0060 ◦ 140

7. 2415332224153322

8.  Counting numbers such as 4 electrons has an infinite number of sig figs because you can not have a partial electron  Conversion factors like 60 seconds/ 1 minute have infinite sig figs because there are exactly 60 seconds in 1 minute

9.  For addition and subtraction look at the right of the decimal point round to the least number of sig figs  Example: 25.2+23.65= 48.85  After rounding for sig figs 48.9  In multiplication and division is depends on the number of sig figs  Example: 20.1*3.6=72.36  After rounding for sig figs 72  Note never round in the middle of a problem wait until the end to round