Back in the old pre-national curriculum days, when we used to be prepared to take a few risks I once - with the school caretaker - concocted a bogus classroom burglary.

We made some pretend footsteps on the mud outside the window, then we opened the window, and we opened all the cupboard doors, and we took away the class tape recorder, which the children knew was always there at the front of the room. Then I waited to see what their response would be.

This was a class of seven to eight-year-olds, in a junior school serving a London overspill estate in Essex, so it wasn’t a school without difficulties, but the children were brilliant. They spotted as soon as they walked in that something was wrong, and that the tape recorder was missing. It was interesting to see to what extent they had the right kind of language to talk about this. They knew all about evidence and clues and fingerprints and so on. I suppose it was from watching television.

This was the response I’d been hoping for and what I needed for the whole thing to work. After all, you can draw up all the lesson plans in the world, but you’re totally dependent on getting the right responses to get the ball rolling.

Anyway, they all got very excited and went off to tell the head, and by this time practically every child in the class had developed a theory about how it had been done, and who might have done it - very sensible ideas about the age and sex of the person, and when it might have happened - and from there the discussion developed into ideas of what evidence they could find to substantiate these theories.

We then got into ideas of comparisons, of measuring the size and depth of the footprints, and their surface area with marbles. They jumped down into the mud to see how deep their own footprints went, and talked about different kinds of shoes and the different patterns on the soles.

From this they deduced that it wasn’t children who had done it, so they went off in twos around the school and started interviewing people and looking at their shoes - telling them they were doing some work on comparing shoes - and from all this they realised it was the caretaker.

He told me later that he could see that the two children interviewing him had realised straightaway that it was him, but they didn’t say a word, just carried on doing the work they said they had come to do, and didn’t give a thing away until they rushed back to the classroom and came to me and said it was Mr Such and Such.

He came along to the classroom after lunch and we explained to them what we’d done, and why. It was all to do with various maths concepts and some work we’d already been doing with shoes, and after that it fed into other work, such as cutting up shoes into their different pattern pieces, and then trying to make our own. It was also a way of getting them really fired up and motivated.

Andy Wright is the head of Rayne County Primary and Nursery School, Rayne, Essex