Great video lectures and ways to build math foundation

I only used Magoosh Quant section only even though I registered for Magoosh Premium. One thing I liked about Magoosh is that they have dedicated app, which you can use to watch your lectures on your mobile during your commute or free time at work. I used their lecture to build some core foundation. I tried most of their questions, but I found them quite different from OG. I don't think they have accurate representation of your score based on their question banks. Thing about video lecture is that it takes ages to go through all of them. I would suggest you to skip some lectures if you are already strong in the particular area and to focus on your weakness.