I just couldn't grasp the concept. I'm not very good at math and that may be why I was struggling with the curves. When I thought I was doing it right was wrong. I had my father take a look to it and he's a math genius so he got it and actually enjoyed the site. I on the other hand didn't really understand the site, but if your good at math like my dad you'd really enjoy a site like this. I spent about an hour all together with being on the site and trying to have my dad explain it to me. I'd only use this in the class room if you have an experienced math group.
Well if you have advanced math experience this site is good, but I had hard time.