Chapter 6 the add and or subtract will not work

Has any one else had this problem? I am suppose to get (2) as an answer but no matter what I subtract that is the correct answer example (9-7=2) and several other combinations. nothing works the board never changes. I have had no problem with this puzzle in the other levels

rustbeck,

Welcome to the pond! On this section, I believe you need to use 3 numbers, ( i.e. I need 2 I would go 9-4-3=2) Try and see if this doesn't work. Good luck and Happy Gaming.