Worth noting that the article is from 2013. I'd definitely heard of Coolmath. It was really popular when I was in elementary school, and I imagine a huge propo

Worth noting that the article is from 2013. I'd definitely heard of Coolmath. It was really popular when I was in elementary school, and I imagine a huge proportion of their hits come from kids during school hours. The reason it does so well is that it's a bunch of arcade-style Flash games, but since some of them are tenuously educational in nature, the site doesn't get blocked by web filters.