Being anxious middle-class parents we're always trying to find ways to trick Arthur into learning. Arithmetic has been a bit of a focus recently, school want him to be better at doing stuff in his head. There's not really a good way to practice that. If you throw random sums at him, or encourage him to count change or add-up number plates in the way you're supposed to (you know, 'make a game of it') he knows exactly what you're up to and refuses to play along.
Without really thinking about it I bought a dartboard on Saturday morning, just because it was cold and I knew we'd be stuck inside all day. And it turns out to be the perfect mental arithmetic tutor. Arthur loves darts (I think it's the magic combination of throwing, danger and the possibility of televisual fame). And he's doing maths in his head without even knowing he's learning. Ha! Next - the campaign for darts in schools.