1. Making Your Measurements Count

2.  All of the numbers I know for sure… + 1 estimate.

3.  Measurements ◦ Non Zero #s ◦ Zeros  Trapped Zeros  Leading Zeros  Trailing Zeros  Decimal Point present  Decimal Point absent

4.  Exact Numbers (Counted items and some conversion factors) ◦ Unlimited or Infinite Significance

5.  The Weak Link Rule ◦ Your answer must have the same number of significant figures as the number in the operation which has the ___________ ___________ of significant figures. ◦ Remember how to round!!

6.  The Weak Link Rule ◦ Your answer must have the same number of ______________________as the number in the operation which has the _________ __________ of _____________________. ◦ Why the add/subtract rule is seldom used in lab. ◦ Why it is used in % error calculations.