Numberpad keyboard does not have negative sign

[lfbettcher]

Catch screen numberpad keyboard needs to be customized to have a minus sign for entering a negative answer. Temporary solution is to add it to the keyboard toolbar, but ideally a custom keyboard will be created that has a +/- button in the lower left where there is an empty space

[lfbettcher]

The current +/- button only seems to get the right answer if it is pressed before entering a negative answer. Pressing it after entering numbers makes it appear to have a minus sign, but the answer is marked incorrect.