I had never seen that key on any keyboard, fascinating 😃
Well, Sabrina, if it can make you happy, Spine can perform some calculations for you directly in the input boxes. I use it a lot for rotations, in the rotation input field it doesn't matter what number is written, I type +120
or -120
and Spine will do the math for me. I think it only works with +
and -
before a number in any Transform input field, but it's still pretty useful.
I guess your calculator button doesn't work for the same reason other things like the "drag the window to the top corner to enlarge it" etc. that are so common in windows don't work as well.
Is it an old keyboard? (guessing because of the dust)