Arithmetic operations inside value boxes

What if Cubase would have simple mathematical operations like addition, subtraction, multiplication, and dividing in value boxes? I just faced a situation when I need to manually edit the wrong defined tempo of an audio file, to get it working properly with the Musical mode. Sometimes I need to open calc to count, but it’s nice to have the ability just put “/2” or “*4” in the value box and get the result immediately without need to leave Cubase even on a second.
In addition to that - boxes, like tempo, has up and down arrows. Maybe it’s also handy to hold Ctrl key while pressing the up arrow and get +10 instead of +1 (or +0.01 in some areas), and while Shift key is pressed - get *2 multiplication. Same for down arrow and subtraction and dividing respectively.
Thanks for your attention!