Free lance Teaching

Instead of doing more freelance during semester period, can I teach 3D max/Viz or Rhino instead to earn extra cash? Imagine that u have 5 student per lesson, each lesson 3.5 hrs for $40, so each lesson I can earn $200. One weekend can earn at least $400, that will be
$1600 per month. Its smarter than doing design. I think I should organised the topic and do teaching. Money is essential for survival, but money should not be the root for all evil. I need money to survive. Do it creatively.