Have a read, and see if you can spot the mistakes!

Chess is a fun game and easy to learn.  You play on a board of 164 squares, which are coloured light and dark, and there are two armies, one black and grey.  The rows are called ranks and the columns are called officers.

The aim of a game of chess is to capture your opponent’s Queen and then they will make a sad face.  The Queen is worth nine pounds, which is the same as three rooks.  If you are in check from a friend it is called check, mate. 

First, have a go at doing some calculation. Pick the best move in a couple of these positions that appeal. They are taken from Aagaard's Inside the Chess Mind, so you can later compare your answers with some 'official' answers from a computer (Fritz 8) but also with the recorded thoughts of some other human beings who tackled the same positions. I've given the opponent's last move when I know it.  Take 5-10 minutes or so for your thoughts and record or write them down if you can (but you can take as long as you like over the Murphy one).