There are forty beaming faces staring up at me waiting for my next move. They giggle as I jump up and down, attempting to sing ‘with a moo-moo here’ from Old MacDonald’s Farm. I know I look ridiculous, but I’m far from caring. It’s 4pm in Cambodia and it’s a searing 40C. We are crammed into a tiny, non-air conditioned make-shift classroom in Phnom Penh. I’m trying desperately to keep their attention as they want to go and play.