Hi,

this calculation overflows with common floating point arithmetics, see for example

http://en.wikipedia.org/wiki/Arithmetic_overflow

There are special algorithms to solve "(126^317) MOD 437" (there has to be, as RSA en/decryption relies on this). However, such special algorithms are out of scope for galculator.

What is in scope for galculator is a warning, when a computation overflows. This is on galculator's todo list and will be part of the next release.

best, simon