This shows not only why I don't use calculators, but an accompanying comment at reddit explains why I can't even help my kids with their algebra. (via reddit)
Honestly a couple of years ago, Princess asked for my help to solve some equations. Once I understood the problem, I showed her how I would do it, which involved a shortcut that made her teacher rather angry. Now I teach the kids shortcuts, but explain that they must only use them to check their work. Until they graduate.