You know, whether or not children should learn up to 12 by the age of nine is debatable, but by the time you're an adult, assuming no learning disabilities you

You know, whether or not children should learn up to 12 by the age of nine is debatable, but by the time you're an adult, assuming no learning disabilities you should be able to do mental math proficiently enough that you don't need to memorize any tables, you can just do it. I hope that person you worked with can at least work a calculator.