sum formulain Quantity

I came from QuickBooks and in there, you can do mathematical calculations in the quantity field.
For example i can input 18*5 in the quantity field and press enter, and the qty field automatically updates to 90.
It would be nice to have in here.

Hello,

this version was added in version 3.1.15. when the new version is released, you will be able to perform these operations in the qunatitiy section of the invoice.