The mathematics „adder game widget” uses gamification naratives. Students are presented with a story of the „evil computer virus that has infected our server and is now spreading to all the tablets. We cannot get rid of it, and it seems that the only way to clean the tablets is that each student plays and wins the game of math knowledge against the virus. And in order to completely expel the virus from the server, all of the students together must solve more math tasks than the virus.