New Year's Challenge

Well yesterday we went out for a meal to celebrate Anne's birthday which is on Tuesday, and we decided to have a New Year's challenge. We had a few different ideas for challenges, (including my suggestion of collecting an object to represent each month throughout the coming year) but the challenge we're doing is a good idea, and that is: To start of with £10 at the start of the year, and to try and increase it's value by this time next year, when the person who has made the most money gets 10% of everyones total, and the rest goes to their chosen charity - if that makes sense. The rules are as follows: No more than ten pounds can be put in at the start Means of increasing value has to be legal Well I've had a few ideas, but still not sure what I'm going to do - so the value of my £10 is still £10