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Stackmode (Polish Notation)

Before you read on: first give it a try... The stack-calculator is a bit similar to an RPN-calculator in the way that is also uses a stack and avoids the use of parenthesis. But it's unique in the way that it has no reversed data entry but follows the 'normal' sequence. You see the entries and intermediate results in the stack which leads to fewer mistakes.

The stack calculator tries as much as possible to accommodate the way of thinking of the user.

  • For operations like add, multiply, divide, etcetera, with two arguments you do the entry as you would expect. So for 5+8, you enter 5 + 8, and press enter (or =) when you are ready to get the result.
  • For operations with one parameter like square, sinus, exponential, etcetera, you enter the operator before or after the parameter. So for sin(2) you can enter a s 2 =, but also 2 a s is okay.
  • Before getting the result by pressing = or enter you can also continue to enter a new operator if necessary to get the right calculation.

Stack Calculator by example

Suppose you have to calculate 34 x (42-19). Just work your way from left to right: 34 * 42 - 19 = =. As you can see intermediate entries or results are placed in the stack. To make it a bit more complicated take the following.


Just work your way from left to right and from top to bottom: 88 - 23 = / 52 + 6 y 0.4 = = =

In the history stack you can see what you have done and check if you didn't make a typing error. The final expression has to be (88-23)/(52+6^0.4) which you can see as a check in the history stack.


The calculator uses the dot as the decimal point, but you can change that to comma in the Options menu (o). 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.

To drop (clear) the stack press d or c s for the complete stack.


For most of the calculations the stack is sufficient. But sometimes you want to store (intermediate) results. For this you can use the Memory block. 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. The Memory block is also used for cashflow calculations. All stack values, last answers and memories are saved on your computer.

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