Elsewhere on this group someone asked about a scale conversion calculator, and it's not the first time it's been requested either. I've always thought this an odd thing, admitting that you aren't able to perform calculations requiring fractions and proportions, something that is taught in the fourth, fifth, or sixth grade in the US.
I guess that's a(nother) problem with our society - we are so willing as adults to just laugh it off when others say: "Oh, I can't do that math stuff. I was never any good at it so I just gave up. Nobody uses it anyway." It's in our culture that this is the norm. It's OK that you can't do these sorts of calculations. "Word Problems" - a national joke. Math is for nerds. No stigma, no concerns, no social negatives.
The reaction ought to be the same as if somebody had said: "Oh, I can't read. I was never any good at it so I just gave up. Nobody uses it anyway." Both skills are equally important in adult life.
BTW, let me cut you off before you guys go off on one of pet tangents, the US educational system. This really has nothing to do with teachers or schools. Please, save your electrons for some other thread.