1. Significant Digits What are they? And How do you use them?

2. Accuracy: zThis is the concept which deals with whether a measurement is correct when compared to the known value or standard for that particular measurement. zWhen a statement about accuracy is made, it often involves a statement about percent error. zPercent error is often expressed by the following equation: z% error = (|experiment value - accepted value| / accepted value) x 100% zAlso see Problem Set # 1-14 in the workbook

3. Precision: zThis is the concept which addresses the degree of exactness when expressing a particular measurement. zThe precision of any single measurement that is made by an observer is limited by how precise the tool (measuring instrument) is in terms of its smallest unit. zHow would you divide the following 1 meter long bar up into smaller divisions? Why? What would your choice have to do with precision? 1 METER BAR

4. Precision and Measuring:

5. Significant Digits: zWhen someone else has made a measurement, you have no control over the choice of the measuring tool or the degree of precision associated with the device used. zYou must rely on a set of rules to tell you the degree of precision. zRefer to the “Rules for determining when zeros are significant” (PS#1-9, workbook)

6. Significant Digits in Math: zUse PS#1-10 to check your understanding of identifying significant digits in measurements. zSee PS#1-11 for the rules about using significant digits in addition and subtraction. zSee PS#1-11 for the rules about using significant digits in multiplication and division. Then go on and do PS#1-12.