This game requires two dice. We also used a paper and pencil to keep score.
It's very simple. Take turns to roll the dice. NB Don't instruct young children to 'throw the dice'. It's not what you want, really ;)
If you roll a double, score 5 points. BUT! If you roll double 6, score 25 points and if you roll double 3, those naughty threes erase all your previous score.
See who can get to 50 first.
This is another idea from 501 Tv Free Activities For Kids. It was quite fun and easy for a five year old to grasp. It was good for practising counting in 5s, but wasn't as mathsy as I'd hoped, since doubles (and therefore points) were few and far between.