Add Charge-Ability to input numbers on keyboard

When adding for example a parking charge on a house account or on a room, we have to use the onscreen keyboard with the mouse to input numbers.  This is incredibly frustrating as we should be able to use the keyboard to do this task.

Why?  Because we have 2 workstations with keyboards which would make it easier to do.  I do not understand why we are restricted to the onscreen keyboard which takes much longer.