1. How do you compare very small numbers? Size of a period: 0.0006 m Size of a bacteria cell:0.0000021 m

2. In this lesson you will learn how to make rough comparisons of very small numbers by using scientific notation.

3. Let’s Review Writing a small number in scientific notation. 0.00000032

4. Let’s Review A Common Mistake Which is larger?

5. Let’s Review Core Lesson What’s the missing exponent?

6. Let’s Review Core Lesson Size of a period: 0.0006 m Size of a bacteria cell:0.0000021 m About how many times greater is the period? Answer: about 300 times greater 3 times 100

7. In this lesson you have learned how to make rough comparisons of very small numbers by using scientific notation.

8. Let’s Review Guided Practice A certain white blood cell is about 0.0000021 m long. A certain red blood cell is about 0.00006 m long. About how much larger is the red blood cell?

9. Let’s Review Extension Activities Research computing speeds of computers from two different decades. How long did it take the older computer to perform an addition? The newer computer? How much faster is the newer one?

10. Let’s Review Extension Activities Research and compare masses of various elements from the periodic table.

11. Let’s Review Quick Quiz A cell membrane is about 0.000005 mm thick. A certain virus is about 0.00009 mm across. How much larger is the virus compared to the thickness of the cell membrane? A human hair is about 0.00012 meters wide. A red ant is about 0.005 meters long. About how much larger is the ant’s length than the hair’s width?