Add support for math operators in number fields

For a faster workflow, it will be nice I can use that 10/2 = 5 directly in a numbered field just like any other Design App. (/ and - and * and +)

Example

The problem

Right now, if I want to move an element/selection/group by a X number of pixels ... I have to do it manually (and compute the new position) .. or I need to add a guideline at the new location and then move the elements.

Possible Solution

Add support for math operators in number fields