Equations Right or Wrong!

This game has a simple mechanism, but playing it is harder than you think! You are shown a simple equation (elementary arithmetic) and have a limited time to choose whether it is right or wrong. Every correct answer earns you one score and your final score is based on the number of your correct answers. If you chose wrongly or run out of time, you will lose! And as it was said, it may look simple at first, but it will become more difficult as you progress.