1. What do you know about these words listed above?

2.  In Science it is important to make measurements that are both accurate and precise.  Accuracy is how close a measurement is to other measurements of the same thinks  Precision is how close a measurement is to other measurements of the same thing

3.  Scientists work carefully to obtain accurate and precise measurements  Scientists also need to know how certain there measurements are.  After measuring something, scientist generally record the measurement as a number

4.  In any number that represents a measurement, there are digits that are certain and one digit that is uncertain.  Think about when you weigh yourself…

5.  Some scales weight go to the tenths place. What would be the uncertain digit?  What has greater certainty? 125 or 124.8? Why?

6.  A significant figure s a meaningful digit in a measured value; the significant figures in a given value are all of the certain digits plus one estimated digit.  The value of 124.8 has 4 significant figures  What is the certain number in 57?

7.  Look at the rules for significant figure sheet that will be passed out. Let’s read through them as a class.