I couldn't praise Khan Academy enough. As a high school student living in Australia, I've been using it for years, and I love how accessible and digestible each lesson is. Khan explains in a way that is so easy to grasp, as he always emphasises the 'why' behind each concept rather than merely giving formulas. I also love the friendly, conversational style of each lesson --- in a way, the minimal editing of each video makes it seem more genuine and warm. As an auditory and visual learner, I couldn't ask for more from the videos. The supplementary questions after each explanation are wonderfully designed and the perfect amount. I actually like the high standards to achieve 'mastery' on this website, even though it seems that some people here complain about the 'one-question wrong ruins everything.' Personally, I like that the website's design pushes you to truly take the time to master each concept and acknowledge each small mistake you may make. It is so gratifying to look at the dashboard and view the palpable progress you've made. This is my first time leaving a Trust-pilot review, but I really wanted to because Khan is honestly one of the people I look up to the most. In today's world, there aren't that many 'truly' not-for-profit organisations that are devoted to making other people's lives better. I think I speak for thousands, and even millions of students, educators... who have gained a little, or a lot, from Khan and his team's devotion. So, from the bottom of my heart, thank you. When I grow up and make money of my own, I hope to donate to Khan Academy's beautiful efforts.