arrow keys click sides of screen on mobile It's 44 pages, good luck. I hope I didn't make a mistake, that would be embarrassing, please correct any mistakes :\ New music, what do you think? I had heard the other one so much that I started hearing it in my sleep. If you haven't already guessed, I have just watched 3Blue1Brown's series on linear algebra and just had to make this explanation, here is the link: https://www.youtube.com/watch?v=fNk_zzaMoSs&list=PLZHQObOWTQDPD3MizzM2xVFitgF8hE_ab Music: Chopin - "The Bees" Etude (Op. 25 No. 2) (played by Daniel Barenboim) If you're wondering why some of the maths is in a different font, it's because some of it was made with LaTeX and imported into Scratch but I was too lazy to do that with everything.