end up with people who don’t recognize that 13+24=87 is incorrect

I had a telecom teacher who would either allow you to use a calculator, but you had to get everything right.
Or go without and you could get away with rougher estimates.

Doing stuff like decibels by hand isn’t too bad if you can get away with a ballpark and it’s a much more useful skill to develop than just punching numbers in a calculator.