HP35S 'Guide for Dummies' being posted online

05032015, 11:12 AM
Post: #32




RE: HP35S 'Guide for Dummies' being posted online
From 3. Introduction to RPN:
Quote:You discover the way to convert °F to °C is: You start with writing the numbers on the whiteboard: 9 5 72 32 But why did you chose this order? Why are 5 and 9 swapped? Most probably because otherwise you'd have to use [x<>y] twice: 5 9 72 32  x<>y / x<>y * Given this example there are two possibilities I would calculate it. Outside in: 5 9 / 72 32  * This is basically how a computer translates the algebraic expression to RPN: Code: echo "(5 / 9)*(72  32)"  bc c Inside out: 72 32  5 9 / * In both cases there's no need to swap any values. Quote:For good measure, let’s try the builtin calculator °F to °C function From a pedagogical point of view this devaluates your introduction to RPN. Why do something in a complicated way when there's a dedicated key for it? Recommendation: You propose to push all the numbers first and only then start with the calculations. But this won't work with more than 4 numbers. Instead you should explain why and when an intermediate result is kept on the stack for later use. Given that there's a builtin function I think that this is a bad example. I'd probably use a grocery store problem like calculating the total of buying the multiple items you need for a cake. Kind regards Thomas 

« Next Oldest  Next Newest »

User(s) browsing this thread: 1 Guest(s)