The last page mentioned sometimes scientists deal with very small numbers. The differences in the wavelength are very small, so scientists use scientific notation. Scientific notation for small numbers works in the same way as scientific notation for large numbers. Let's go through a few examples, and then you can do more practice problems in the interactive lesson that follows this lesson.

1. In this situation you would count how many places after the decimal you go before the decimal falls after a number other than zero. For this number, the answer is 3. If the number was .0000145, then the answer would be 5.

2. Now move the decimal past the first non-zero number, which in this case is 1. You should have 001.45. Get rid of the extra zeros so you have 1.45.

3. In step 1 you found out that there were three decimal places before you received a non-zero number. Take that number and add it to the top and right of the number 10 to make 10^-3

4. Combine the two numbers to make 1.45 x 10³. That's it! The number is in scientific notation.

Let's do another example:

1. .65 / 900 = .000722

2. The number of places from the decimal to the first non-zero number is 3.

3. Move the decimal one more place, to be after the 7, and you should get 0007.22. Get rid of the extra zeros to make 7.22.

4. Take the number from step 2, which is 4, make it negative. Put it as a power of 10 so you get: 10^-4.

5. Combine the two together to make 7.22 x 10^-4