How do you work out how to find a % of a number on a calculater

A simple way to go about finding a percent value is to divide the new number by the original number. this will in turn give a decimal value. the returned decimal value can easily be converted into a percent (out of 100) value by multiplying by 100.
ie: 2 divided by 3 = .666667, or around 67% 6 divided by 4 = 1.5 or 150%
as far as i know there is no direct function to calculate percentages built into many calculators, although a small few do in fact have that ability.
hope that helps :)