I think your comment about Nintendo's is shallow and missplaced. You have a situation with those who are trying to make ends meet, working multiple jobs, and both spouses working, Nintendo might be the only babysitter they can afford.
Also teachers who are invested in making sure your kids have the best education they can have so they have the chance a the american dream and invest their own money in that effort (for your kids, not them) from their meger salaries are the real Americans that are fundementally supporting the American dream. It would be better long range thinking to fund our kids education over say, supplying high tech airplanes and drones to go off and rain terror on some other country.
We have our priorities wrong on a Federal level.
Those teachers should be applauded for that activity not told to let the kids and their parent figure it out for themselves. That would get us more into those families that can afford the calculators and those that can't. Isn't it better to have an even playing field for at least the time the kids are in school?