Re: What calc for my 7 years old son? Message #9 Posted by Vieira, Luiz C. (Brazil) on 26 Oct 2009, 8:34 p.m., in response to message #7 by DaveJ
Quote: Forcing him to use a calculator that requires "1 ENTER 2 +" is just silly IMO.
It is well known that Algebraic Notation and Reverse Polish Notation are, as their names say, notations, and not expressions. When one reads1 + 2 and thinks of 3 it does not mean a sign of 'equal to' is demanded somehow, somewhere. And when one writes 1
+ 2
____
3 it does not mean a '=' is missing somewhere to finish the calculation. If we write '1 + 2' and say 'is equal to', then we do not need to add a '=' sign.
Considering RPN a silly notation is considering the closest notation to what one writes in a paper to perform a handwritten calculation silly, too. When we add, multiply, divide, compute a square root or whatever calculus that can be performed with paper and pencil, not one single time a '=' is needed. It can be used, mostly to indicate an answer, but it is not needed to perform calculations.
When we are writing down equations then it is another story, '=' is used to separate left and right sides of it. But we are talking about calculators, number crunching, not expression evaluation. RPN and Algebraic Notation live together in many new HP calculators, it is just a matter of what one wants to do.
And yes, HewlettPackard designers took advantage of the natural assembly language coding, which is closer to the actual calculations themselves, where adding A to B is expressed with the mnemonics add A,B and again, no '=' is demanded. Allowing A and B to be available and located prior to add them is the key for RPN operation, so [+] means add Y,X. Maybe my point is too focused, but I actually began reasoning and solving problems better after reasoning in RPNfashion. I still do today, and this is due to RPN existence and a notation. I never dealt well with Algebraic Notation and I believe because it is not too close to the actual calculations, and my first calculator was a TI57 (1980, still with me). My second one, an HP41C (1982, still with me, too) actually helped me a lot more.
Cheers.
Luiz
Edited: 26 Oct 2009, 8:40 p.m.
