1. Warm Up #2
What tool would you use to measure the volume of a rock? How would you do this?

2. Lesson 2: Measurement and Scientific Tools
Nature of Science (NOS): Scientific Explanations

3. Essential Questions
What is the difference between accuracy and precision?
Why should you use significant digits?
What are some tools used by life scientists?

4. Description and Explanation
Description – a spoken or written summary of observations
Qualitative description – uses your senses to describe an observation
Quantitative description – uses numbers to describe the observation
Explanation – an interpretation of observations

5. International System of Units
SI Units – an internationally accepted system for measurement
A prefix can be added to a base unit’s name to indicate either a fraction or a multiple of that base unit
Based on powers of 10

6. Precision and Accuracy
Accuracy – a description of how close a measurement is to an accepted or true value
Precision – a description of how similar or close measurements are to each other

7. Significant digits – the number of digits in a measurement that are known with a certain degree of reliability. Includes all digits known for certain plus 1 estimated digit
Rules (pg. NOS 15)
1. All nonzero numbers are significant.
2. Zeros between nonzero numbers are significant.
3. Final zeros used after the decimal point are significant.
4. Zeros used solely for spacing the decimal point are not significant. The zeros indicate only the position of the decimal point.

8. Significant Digits Activity
With the person next to you determine which numbers are significant using the rules.
4.05
0.0025
1,500
0.500

9. Scientific Tools
What are different tools that scientist use when they are performing a scientific investigation?
Pass out Scientific Tools handout