Bill and Bernie are playing a game to find out which coins (1p, 2p, 5p, 10p and 20p) roll down a hill. They discover that a 20p coin doesn't roll very well, as it isn't round like the others. They then add up the total amount of money that rolled (1p + 2p +3p + 5p + 10p), showing the answer at each step in the calculation. The difference between the amount which rolled down hill and that which did not is then calculated: 20p -18p = 2p.
Children could have a 'coin sports day'. Events could include throwing coins into three hoops - the first hoop would be the value of the coin; for the second hoop, multiply the value of the coin by two; for the the third and furthest away, multiply the coin value by three. The children could then add the values they have thrown and subtract their total from £5.