Best Way to Catch Up in Math in High School and Self-Education Board Posted July 11, 2019 24 minutes ago, katilac said: My favorite math prep resource is ALEKS online. It's $20/month rather than free like Khan, but I think well worth it if you have the money. I find it much quicker than Khan because it does a thorough assessment for whatever course you're enrolled in and then has you work on what you haven't learned or mastered. You can choose from a list of 'ready to learn' topics, but it won't let you choose a topic it hasn't deemed you ready to learn. Or, you can just keep moving down the learning path if you don't want to make choices. I personally think it's easier and more reliable than evaluating yourself and deciding what you need to work on (and in what order). Khan has the mastery challenges but that takes longer than just doing an assessment, ime. They have both ACT and SAT math prep. I was looking at this one and it seems like exactly what she needs but the reviews online weren’t very good. I will have to give it a second look now.