1/9998 = 0.0001 0002 0004 0008 0016 0032 0064 0128 0256..

Re:1/9998 = 0.0001 0002 0004 0008 0016 0032 0064 0128 0256.. by zoul on Thursday January 30, 2014 @01:37AM (#7149351)

The sequence is a shortcut accepted by the vast majority of regular calculators for most of operations. It simply takes the second operand to be the same as the first and repeated pressing of the = key repeats the operation ad infinitum. Ie. 1+== is 3.

I have written an iOS calculator app and had very interesting times trying to find and mimic these shortcuts. I have thought for a long time they had to follow from some simple implementation detail, as all the calculators got them precisely the same, but I never found this one consistent rule, I had to implement the features in a series of hacks.

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Re:1/9998 = 0.0001 0002 0004 0008 0016 0032 0064 0128 0256.. by pushedx on Thursday January 30, 2014 @02:29PM (#7152806)

This site [1] reveals the secret to that pocket calculator shortcut and a few others, and also provides useful algorithms for calculating things such as square roots and logarithms.

[1] http://tedmuller.us/Math.htm

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Re:1/9998 = 0.0001 0002 0004 0008 0016 0032 0064 0128 0256.. by jloughry on Thursday January 30, 2014 @02:52PM (#7152930)

Wonderful! That site gives tests that can be performed from the keyboard to distinguish between Casio and non-Casio architectures, mentions the invisible 9th digit of precision, and notes that some calculators get it wrong.

The old Sinclair pocket calculators had some known arithmetic inaccuracies.

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