HN Explorer

Calculating percentage on a calculator

1 points by dugluak ↗ HN
Why is calculating percentage on a typical electronic calculator (or the one on your phone) seems so counter intuitive, especially when you have a special % button ?

If I want to calculate 20 percent of 340. Why cant I simply press 20 % 340, instead I have to do 340 * 20 %.

5 comments

[ 4.7 ms ] story [ 39.3 ms ] thread
anibali
If you take "percent" to mean "divided by 100" (which is all percent is), then it makes perfect sense. That is, "340 * 20 %" is "340 * 20 / 100". Would "20 % 340" be more efficient for some use cases? Probably, but it would be giving "%" a different meaning.
Someone
One reason could be that there also are "if I want to add 20% to 340", which on most calculators is "340 + 20%" and the similar "340 - 20%" to subtract 20% from 340. I'm not sure which of these should be assigned to the shorter sequence you propose.

Another may be "because that's how calculators always have done it".

[deleted]
(comment deleted)
jaclaz
3.4 * 20 saving two keystrokes? ... ducks ...
dugluak
You didn't use of the % button. Still not as intuitive as doing addition, subtraction, multiplication and division of 2 numbers.