Put the children into teams, in lines, as you would for a relay race. Some distance in front of each team (depends on the space available and the age of the children.) place laminated cards with a 4 x 4 grid on them with some squares filled in. Either put large sheets of paper and pencils next to the grid or give them dry-wipe pens to write on the bottom of the grid. Click here for a download.
The code should enable another person to take the appropriate steps from top left hand corner to bottom right and show where the filled in squares are.
They will have to decide as a team how they are going to show the black squares and how they are going to show the steps.
First player in each team runs up and writes the first coding symbol, runs to back of line. Next player runs up and checks the code so far and adds the next bit of code.
The fastest team have to have their code checked before being declared winners. If the code is wrong, continue playing with remaining teams.
There are loads of variations. A lot depends on how many children and how much time you have. So, you could shorten the game by telling them that each child is going to code as far as the next black square. Or each runner could write a line of code. For more experienced children, include some grids where there are repeated patterns so that they have the chance to incorporate loops or procedures
There will almost always be a problem at the end of a line – do they do a right turn and another right turn and continue to program from right to left etc or do they start again from the left for the second line. Discuss this!