[quote]...a real computer will tell you the answer without having to pre-calculate a rough answer! <hr></blockquote>
Not true! Electronic computing devices are not infallible. Apart from failures of the device there is also the 'garbage in - garbage out' problem.
Unless you have some idea of what the answer should be, how will you know when the electronic brain gets it wrong? And it will get it wrong.
As for using a circular slide rule, only practice will enable the user to become adept. I find some problems can be solved quicker using a whiz wheel than a calculator.
If one type of whiz wheel is awkward, try using a different type eg from the 'slide' type to a 'CR' circular type. The CR5 from Jeppessen is my favourite.
[ 08 January 2002: Message edited by: Tinstaafl ]</p>