They also can do arithmetic in their heads.
Ask a post-calculator generation "youth" what 60% of 5 is and watch them reach immediately for their phone. If they can figure out how to set up the problem, they will use the calculator function. If not, then they'll Google the answer. It's a scream.
0.6 X 5 = 3
Good. Now tell me why I handed you a $10 bill and a $1 for my $5.63 hamburger.
You have to reassure them that it will work; just punch it into the register. kek