Because quantum mechanics is physics that describes the interactions of very small objects (i.e. molecules, atoms, and electrons), this week you will need to know how to multiply very small numbers.
Remember that scientific notation writes very small or large number in terms of powers of 10.
For example, .0008 can be written in scientific notation as 8 x 10-4 or as 8E-4. The power of 10 (-4 in this case) tells you to take the number 8.0 and move the decimal 4 places to the left giving us .0008.