That's a silly argument, because arithmetic is so simple people pick it up in spite of their use of calculators. Hell, people learn simple arithmetic even if they've never had any schooling (they can tell you that 5 apples and 3 apples makes 8 apples, things like this). And arithmetic with big numbers is so tedious regardless of how well you know it that it's better to just use a calculator, and people have always done this (before digital calculators you had an abacus, multiplication tables, and many other similar instruments).

Calculus or programming or advanced algebra etc are nowhere near the same difficulty, and the same rules don't apply.