The calculator widget seems to not be handling some cases of the modulo operator correctly.

| Expression | Kagi Widget | Actual |
9 mod 3 | unknown | 0 |
5 mod 1 | unknown | 0 |
5 mod 0 | 5 | undefined |
It looks like the main issue is that the widget is displaying unknown when the result should be 0. The other issue is that the widget is evaluating expressions like a mod 0 to a when it should be undefined.
These results could be potentially misleading to students who might not have a good grasp of the operator yet.