Take your class on a Duck Hunt to the lake!
Have them answer a question and they can go huntin'. There are twenty one ducks for them to try and hit (with their fingers and an Interactive White Board) to give them points! The ducks paddle at varying speeds across the lake and only disappear once your students have "hit" them to get the points (all of them have different points, none of which your students will know before "hitting" them!
Follow Matt-Erials on Twitter for an exclusive Duck Hunt Score Sheet!