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All the calculators that I just tried for the article's expression give the wrong answer (HP Prime, TI-36X Pro, some casio thing). Even google's own online calc

All the calculators that I just tried for the article's expression give the wrong answer (HP Prime, TI-36X Pro, some casio thing). Even google's own online calculator gives the wrong answer, which is mildly ironic. [https://www.google.com/search?q=1e101%2B1-1e101&oq=1e101%2B1 https://www.google.com/search?q=1e101%2B1-1e101&oq=1e101%2B1] I played around with the macOS calculator and discovered that the dividing line seems to be at 1e33. I.e. 1e33+1-1e33 gives the correct answer of 1 but 1e34+1-1e34 gives 0. Not sure what to make of that.

Const-me 2y ago
> the dividing line seems to be at 1e33.. Not sure what to make of that That’s not too bad. They are probably using hand-rolled FP128 format for their numbers. If they were using hardware-provided FP64 arithmetic, the threshold would have been 2^53 ≈ 9E+15: https://en.wikipedia.org/wiki/Double-precision_floating-point_format#IEEE_754_double-precision_binary_floating-point_format:_binary64 https://en.wikipedia.org/wiki/Double-precision_floating-poin...
qwezxcrty 2y ago
Tried with the HP Prime and it gave the precise 1 for the test. One need to put it in the CAS mode and use the exact form of 10^100 instead of 1E100. You shall get the right answer if the calculator is instructed to use its very powerful CAS engine.