The sad part is when i was in tech school (high school tech school not those crappy vocation schools that pretend to be college) (graduated a little under 10 years ago in 01) Class based IP addressing was taught as THE way to do subnetting ... if i remember we had 3 different tests on it. So I'm not surprised they are still teaching it. Heck I hadn't even heard of CIDR till i took a CCNA course 2 years later. 

As for Class based IP addresses are dead, i would suggest an edit to [Subnetting Wiki](https://serverfault.com/questions/49765/server-fault-wiki-how-does-subnetting-work) that explains class based addressing is dead as the master question.