Move counter increments on nullified illegal moves.
Illegal moves will in many cases increment the move counter, even though the change of the board that would have followed that move is cancelled. Here are the three situations I've encoubtered this bug:
-After adding a number to one side, but before adding the same number on the other side, if you try to add soething else, cancel multiples of 1, cancel two opposite numbers on the same side of the board, or similar, the game will not let you, but it still coubts as a move.
-While you are in the process of multiplying or dividing the entire equation by a number or variable, the same problem occurs. This is especially a problem, since the margin between multiplying and dividing can be pixel thin.
-attempting to remove a lone zero (or vortex) on one side of the equation will result in incremented move count, even though the zero does not disappear.