First off, if you haven't visited iSciFiCalc on the app store, then please go to it at this link.
iSciFiCalc is a RPN scientific calculator and a fraction calculator with fun and artistic interfaces. It will eventually have a financial calculator included with it. RPN stands for Reverse Polish Notation. RPN calculators can do the same thing as other calculators. If you take a look at the picture, see if you can see anything missing that you would expect a scientific calculator to have. If you can’t find it, the missing feature is parenthesis. Parenthesis on RPN calculators do not exist because you can get the same answer quicker using a different way. RPN calculators use a stack. Everytime you click the "enter" button (far right on bottom of picture), it pushes the number that you have currently onto a stack of numbers. You can enter as many numbers as you want and you don’t have to do any operations with them until you want. So, if you punch in 54 then click "enter”, 45 then click "enter”, 78 then click "enter”, and then click “+” and “-", it will give you the answer of -69. What it did, was add 45 and 78 together and then subtracted the answer of that, which is 123, from 54 and gave you the answer of -69. RPN calculators cut down on the number of digits you need to press get the equivalent of other calculators. Once you use a RPN calculator you won’t want to go back. The infix expression "5 + ((1 + 2) * 4) − 3" can be entered like this in RPN:
5 "click enter", 1 "click enter", 2 "click enter", "+", 4 "click enter", "*", "+", 3 "click enter", "−".
The expression is evaluated left-to-right, with the inputs interpreted as shown in the following table (the Stack is the list of values the algorithm is "keeping track of" after the Operation given in the middle column has taken place).
Input | Operation | Stack Comment
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5 Push operand 5
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1 Push operand 5, 1
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2 Push operand 5, 1, 2
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+ Add 5, 3 Pop two values (1, 2) and push result (3)
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4 Push operand 5, 3, 4
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* Multiply 5, 12 Pop two values (3, 4) and push result (12)
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+ Add 17 Pop two values (5, 12) and push result (17)
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3 Push operand 17, 3
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− Subtract 14 Pop two values (17, 3) and push result (14)
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When a computation is finished, its result remains as the top (and only) value in the stack; in this case, 14.
More on Reverse Polish Notation can be found on Wikipedia at this web page.
iSciFiCalc since it's last update, now includes a fraction calculator, to tackle those nasty fractions that everyone hates to do. Type in your fraction, choose your operation, type in your next fraction, click equals; it's that simple. The calculator also displays the mixed number and the decimal equivalent of every fraction.
If you are looking for support for this application please see the support page.
