DS says quite different, I am not able to compare.
DS did Intro to Number Theory via textbook. I read the online courses were different so we tried this one out (you can drop before the 3rd lesson and get a refund). DS said they do not use the book at all- similar topics but different descriptions, etc. He likes the online course very much so we plan to also repeat Intro to Counting and Probability and Intro to Geometry. I am happy to slow him down a bit.
I originally thought I could save by just having him self-study but am ok to pay if he finds online course useful.
