Smiley Math Subtraction

Help Smiley clear the board by finding and collecting the correct answers for the subtraction problems. No time limit but you'll need to stay on the move to avoid the monster.

Click or tap a space horizontally or vertically adjacent to Smiley.  These locations are highlighted in yellow.  Once you've moved Smiley over the answer to the given subtraction problem, just click or tap Smiley.  To complete a level keep collecting the correct answers until the board is cleared.  You'll lose a life if the monster gets Smiley or you get a wrong answer.