I am beginning to get intrigued by how the self-service checkout machines in supermarkets calculate change. It is obviously not on the principle of smallest number of notes/coins – for example yesterday I was given 4 x 2p plus 1 x 1p rather than 2 x 2p plus 1 x 5p - but somehow takes account of what is in there.
Are they trying to minimise the number of notes & coins they are left with at the close of business?
Anyway, I am impressed.
