The thing is $#*!, you can't learn a thing, It $#*!ING $#*!, get 1 thing wrong, you have to redo whole $#*!ING PRACTICE/TEST/PRETEST a good score. The thing should be banned and the videos don't teach you anything, they just explain.The pratices give you a headache, The thing is $#*!ing stupid, Do NOT USE THIS $#*!ING website, IT WILL TURN YOU INSANE AND KILL YOU. IT WILL SEND YOU TO HELLLLLLLLL! I HAVE it a 1 star/rating though it should get a -1 star/rating(also spread the word that Khan acdemy is BULL $#*!ING $#*! $#*! $#*! $#*!ING STUPID!)