In this video I cover the divisibility rules which help you figure out if a number is divisible by 2, 3, 4, 5, 6, 7, 8, 9 or 10. They're the next best thing to actually, you know, memorizing your times tables. Did you get that hint? Memorize your times tables already! Gotta be a good app for that.
Factoring - Let's review!
If you're already a factoring master, feel free to skip this video. But if you haven't factored in a while you might want to watch it, since factoring trig equations is going to be twice as difficult as factoring with just x. For even more factoring practice, especially if you have a tough teacher, check out the Algebra 2 factoring page.
Hard Factoring Problems (free)
Don't let your teacher confuse you! In this video I encourage you to forget what you know about factoring and come at it with my tried-and-true "trial and error" method, which over the years has saved many of my students from factoring oblivion.
Equations of Parallel & Perpendicular Lines (free)
The SAT, in particular, emphasizes being able to find the equation of a line perpendicular to another line. [hint: "negative reciprocal" is gonna help] Later math and science classes use this property too, so it's not a complete waste of time.
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...)