Math Game for kids

I use this site for my kids math review. I would like to spice it up a bit by adding my own custom messages, pictures, video clips and/or images for the correct answer. "Great - tonight you get to watch a movie." Or you get ice cream for getting a 30 problems correct. or for an incorrect answer - "Cmon, that was easy, you can do it if you try harder, etc and maybe be able to show a funny picture from vacation, etc) Or be able to custom message for time events (1:00 - Cmon Megan, you can do it - one minute to go") [login to view URL]