This activity is always a hit with my students. When we are working on stations during our decimal unit, I use this activity on the Promethean or SMART board. There are over a dozen problems reviewing decimal operations and decimal word problems.
How does it work? When the students identify their answer to the problem - and if it is correct - the balloon POPS! Sound and all. (Incorrect answers stay on the screen, no popping, no sound; so that they can make another answer selection.)