Doubling, halving, tripling and thirding and more is an understandable strategy. I would recommend this nice and easy strategy to other people. Its not complicated and once you get the hang of it you'll say, "Boy that was soo much fun!" Sometimes it can get a bit hard, when you go up to higher numbers, and you don't know what to triple or third. When you double and halve, the numbers get easier and even, and it's easier to figure out the solution!