It’s so bad and crappy
First of all, it’s super glitchy and second the man’s voice is awful. Sounds like a robot from 1931. And then if you tried looking some of the math up on other websites, it’s wrong but teaching textbook says it’s true on the first. It said that in the UK they used the standard system or imperial which is not true and they have not used it since the 1970sand I was wrong and it they said it was true and so it was really annoying so don’t use this. They have incorrect math.