Is it often flat-out wrong where you live?

My most-common frustration with it is when products I want to compare don't have the same quantity-denominator. (Either a different unit, or sometimes a different dimension like weight versus volume.)

I've many times seen it wrong but more often the same item will have some tags expressed on cost per ounce, others per lb, etc. To discourage comparison. But I dont think people are paying much attention to those numbers anyway. Math has become a scary topic for them altogether.