I saw an article on Forbes this morning. Sure, it was in the blogs part of the web property, but it had the Forbes logo header at the top of the page. I expected the content to have a certain level of professionalism. I stopped reading at the second paragraph because the author wrote "There are some women, but there are way more men then women." Then women what? WHAT DID THEY DO?!
I couldn't find a guide to teaching the difference between the two words that I like, but here's one that is very practical: wikiHow: How to use then and than