Now I see what you are saying. if you look at my first screenshot above you'll see that I have this little triangle before the text box (actually it is cross because a value is entered, but I have these triagnles before all the input controls), if I click on any of triagnles it will open a popup dialog where I can put a whole crazy macro program if I want to. In you case there is no triangle and text box forces you to enter only numbers here :(.
I have 8.2 version and Enterprise marketing solution full version (I have these "triangles" everywhere and I've had them in 6, 7 etc).
My guess is that you Kentico installation is somehow limited. If upgrade is not an option you can always get the same results with repeater and for instance boostrap accordion.