It was wonderful to project the ipad with my document projector (or Elmo) so that everyone could see it. My hubs found this awesome app called Math Board that gives problems with multiple answers. There are loads of variables that you change on it to fit your class or child's needs: timed or untimed, multiple choice or not, amount of numbers, how large the numbers, operations, etc.
To make it more interactive, my kiddos were using base ten blocks to solve and show their answer. They had a great time taking turns to come up and select the answer or to read the math problem to the class.
I'll definitely be using this again today so that all of my students get a chance to push the answer!