C) Number Format

Numbers can be formatted to any number of significant figures, to scientific notation, to express the date, etc.

Select column A
Click on Format
Click on Cells
Click on Number
Click on Number
Click on 0.00
Click OK

Look now at the numbers in column A

Select column B

Click on Format
Click on Cells
Click on Number
Click on Scientific
Click on 0.00E00

(note the significant figures can be changed by deleting or adding zeros to the edit line in the bottom of the dialog box)
Click OK