If you have an interactive board you can draw on, this one is great. If not, open PPT in presenter view and draw using the pen tool (or on an second device (iPad) and counters will appear in real time.

Two teams, everyone has a whiteboard and pen. Announce the calculation, everyone gives it a go - boards up - pick one correct answer(er) from each side and have them move their counter one place. Click to the next slide and pumpkin will magically move!

Really easy to adapt this to phonics and modern languages, even notation in music!