What is it?

Mouseless RPN-Calculator is a light weight online calculator based on Javascript. All calculations can be done by use of the keyboard, so no time consuming mouse clicks. RPN stands for Reverse Polish Notation and it saves you time as it avoids the use of parenthesis and brackets.

Main features

All the advantages of RPN

Keyboard for all data entry (as you would expect from a calculator)

Most frequent used instructions only need 1 key; other instructions 2 keys

2 x 20 visible memories to store intermediate results and to perform special calculations

History sheet ('paper tape')

Stack and memories are saved on your computer for future use

Copy results to clipboard for use in other programs

Mathematical calculations

Statistical and probability calculations

Financial calculations like CAGR, Annuity and CashFlow

Physical constants and conversions

Why RPN?

RPN does not use parentheses. You enter numbers and instructions similar to the way you learned math on paper. You first give the number(s) and then tell what to do with it. It's a bit different than you're used to, but it is logical and faster. Another advantage is that you can see the intermediary results as you perform your computations rather than just the answer at the end. This allows you to check the results and correct errors more easily. It's easier to follow the stream of calculation. On an algebraic calculator, omitting an opening parenthesis, may not lead to a calculation error until much later when an entire subexpression is evaluated.

RPN by example

Suppose you want to calculate 45 * 321. There you go: 45 [Enter] 321 [*], et voilą.
Now suppose you have to calculate 34 * (42-19). Just work your way from left to right: 34 [Enter] 42 [Enter] 19 [-] [*]
As you can see intermediate entries or results are placed in the stack. To make it a bit more complicated take the following.

  88 - 23
------------
(52 + 6)^0.4 

Just work your way from left to right and from top to bottum: 88 [Enter] 23 [-] 52 [Enter] 6 [+] 0.4 [y] [/]
In the History frame you can see what you have done and check if you didn't make a typing error. To copy the result to the clipboard press [c][c].

The calculator uses the dot as the decimal point, but you can change that to comma by pressing [o] for notation and then press [d]. To enter negative numbers: enter the number and then press [n] to change the sign. The calculator also accepts numbers in scientific notation. Use [e] to enter exponent; [Shift-e] for negative exponents.

Memory blocks

For most of the calculations the RPN stack is sufficient. But sometimes you want to store (intermediate) results. For this you can use the Memory blocks. Just press [m] to store the value from the x-stack to the first free memory place. Or use [s] followed by a character to store it on a specific place. Use [r] followed by a character to recall a number. There are two Memory blocks with each 20 memory places. You can cycle through the Memory blocks by pressing [z]. As you will see there is a third Memory block that is specifically used for financial calculations. All values in the Memory blocks are saved on your computer if your web browser accepts cookies for this site.

---

Mouseless RPN Calculator by Frans Schrijver, fsch0203 at gmail dot com, Copyright (2008): GPL