This video explains what contingency tables (i.e. two-way tables) are, how to fill in the totals at the end of each column in row, and how to do basic calculations from them.
Computing Probabilities from Contingency Tables (2 Way Tables)
This video shows the easy way to compute independent probabilities, proportions, and the thing that these tables are really great for, dependent probabilities. These tables are so great, you'll find yourself drawing them even when you don't have to because it's so much safer than using formulas blindly.
Backwards Contingency Table Problems
This video shows you how to do a very particular type of two-way table problem, where they give you a table with blanks in the middle (or you construct the table yourself as part of a word problem) and then you have to use the other values in the table -- including row and column totals -- to work "backwards" to find the missing data.
If you do not have an account, you should get one, because it is awesome! You can save a playlist for each test or each chapter, and save your "greatest hits" into a "watch right before the final" list (not that we recommend cramming, but when in Rome...)