1. Sanders P-7 Percent Error Prologue

2. Prologue Unit Measurement In science, one of the key components of observation is measurement. Scientists use the metric system to measure. The metric system, or System International, uses base 10.

3. Prologue Unit Basic Units of Measure The gram is the basic unit of measure for mass. –A paper clip is about equal to a gram. The liter is the basic unit of measure for volume for liquids. –Cubic centimeters for a regular shaped object. The meter measures length.

4. Prefixes Kilo Hecto Deka (Unit) deci centi milli One thousand x 1000 One Hundred x 100 Ten x 10 The unit itself x 1 One tenth x 0.1 One hundredth x 0.01 One thousandth x 0.001

5. Prologue Unit Mnemonic King Henry Died Uniquely Drinking Chunky Milk Kilo Hecto Deka (Unit) deci centi milli

6. Prologue Unit Errors Errors are made in measurement. To find our how badly the error was made there is a formula for determining the mistake.

7. Percent Deviation from Accepted Value Please include the following equation to the front page of your reference table.

8. What is Percent Error? When you get a 98% on a test, you did well. 98% represents percent correct. Your percent error is 2% The smaller the number, the less error there is.

9. Why percent error? When performing calculations, scientists need to understand if their calculations were correct. In other words, how far off were their observations or measurements.

10. Calculating Percent Error Throughout this school year, your will be checking your work by calculating percent error. It is a self check that your work was done correctly.