Long Reals
No. It is just that slide rules went out in part because they don't keep
track of decimal points for you, and pocket calculators do. The problem
gets worse when you must do 1,000,000 calculations, and some of the values
are multipled by 3.45% (.0345 or four decimal places) while others are
multiplied by 16.1% (or three decimal places). Computers keep track of
things like that much better than people.
Of course, I don't even want to talk about rounding errors (1/10 is a
repeating decimal in binary).