Loud Math

These boys look so sweet and quite here it might be hard to believe that a few minutes before they were running around the apartment screaming like maniacs.
When I finally caught and questioned them the game was explained:
We are playing Indiana Jones (Stefán shows his Taekwondoe belt that was used as the whip). Each guy gets 12 lives. I already killed Einar9 times, so I only have to do it 3 more then he will be really dead, then he kills me 12 times.
And I thought it was totally destructive play, I had no idea they were learning at the same time.
So Stefán's math is coming along very well, but my head hurt from all the noise so the lessons need to take a little break.