Inter text to text obj by keyboard

I’m dev a little tool to help me solve my homework fast.
I’m almost complete the tool but it needs a last feature which ِability to inter number by keyword
I mean click on the box and inter number(this just for Vt , Vl and Vin the rest value PF and Theta come by calculation)
The Question how I do that
I attack the blend files. you can run the game everything work
voltageVector.blend (851.1KB)