How to change the "cut"

Hello all! It's been about two years since I last worked with S4S. I'm having some trouble changing the cut of an object in Blender. I'm not working on anything too fancy, just importing a single .obj file to act as a new copy of a lawn gnome. When I try to change the cut, however, it won't let me insert a number. Nothing can be typed at all. This is such a beginner issue but I can't find a workaround! lol Thank you in advance! (It's good to be back)