Keith the Thief is going to steal the biggest diamond you've ever seen.
Everyone watches the website game Don't be Alarmed on the whiteboard. There is a picture of a dark room containing what looks like a million-carat diamond in a secure glass display case. Keith must get around three alarms - one on the window, a pressure alarm on the floor, and one on the case that holds the jewel. The pupils are tightly focused as they try to navigate him across the various sensors by deciding which wires should be cut. Strident bells ring if they make the wrong choice.
Then pupils listen intently as Sarah Neild, ICT co-ordinator for Birchley St Mary's Catholic Primary School in Billinge, near Wigan, asks them to think about how computers control things. One eager child says: "You know car keys - you can use them with a sensor to open the door." Another pupil adds: "Well, on Top Gear they said if you put the car key with the button next to your head the signal's stronger and you can lock your car from further away." Ms Neild looks surprised and promises to try it out later.
The discussion moves on: traffic lights that can sense the density of traffic, security lights that come on when there is an intruder or when the light fades, traffic barriers that are raised as a car approaches, or counters that show when a car park is full.
Pupils at level 5 are expected to understand how devices can be used to monitor and measure external events using sensors. In order to meet these requirements, Ms Neild bought an external control box (FlowGo) to link the computer to sensors (switches, light sensors, pressure pads) and output devices (light, buzzer, motor).
This is the first lesson in a series of five, and she has been meticulous in her preparation. The class has been arranged in mixed-ability groups of three. Sixteen pupils sit on the carpet while the other 16 sit behind desktop computers. There are three laptops in the centre, set up with three FlowGos control boxes. Ms Neild, a finalist in this year's Becta ICT in Practice Awards, has support from a student teacher for the lesson.
Flowol is a software flowchart that helps students to understand the process of modelling control. They can design and build a series of on-screen actions in the flowchart. It is a bit like building a short computer program, requiring a logical, systematic approach. If one action happens, another should be triggered. Flowol is adaptable and easy to use.
It has a simulation mode with on-screen control scenarios - this allows pupils to learn to use the program and see the effect on screen before moving on to controlling a model via an interface. The FlowGo interface is a kit that is designed to operate with small electrical components, such as bulbs, buzzers and motors.
With a combination of real models and on-screen simulations, pupils can learn how such systems are created and how they work. All of the work in this lesson meets the ICT and Damp;T programs of study for key stage 2.
Next, the task - to devise a set of instructions to monitor the front door of a house - is introduced. Is the door open? Is it closed? The door will act as a switch. If it remains closed, the computer will keep monitoring, but if it is opened, a light comes on and a buzzer sounds to raise the alarm. Now comes the real thinking: how do you get out of the house without raising the alarm? The room is very busy and there is a buzz of excitement.
ICT is being used here not merely as a presentation system but as a means to develop higher-order thinking skills. The lesson uses simulations and models to answer "what if" questions. Pupils also work on creating, testing, improving and refining sequences of computer instructions on-screen. They monitor events and respond to them - changes in light levels, temperature, detecting light levels and turning on a light.
By the end of the fifth week, Ms Neild expects pupils to be able to explain how window security and central heating monitoring systems work, why sensors act as switches, and why the computer has to check continually to see if switches have been pressed. She uses evaluation sheets to encourage pupils to reflect on what they have done.
"There is a lot of logic in the work," she says. "Pupils have to work through a sequence of actions, some of them quite complex. The great thing is when they rethink their sequences. Instead of just saying that it doesn't work, they work out why it doesn't work. The software gives them the opportunity to work it out, boosting confidence in their ability as problem-solvers.
"But it's not all computers. I like to do some of the work away from the computers so they can think things through. Once they get to the computers they support each other - I wouldn't want to stop that. And I can scan the room to see who is having problems."
Control is often cited as an area of ICT which teachers tend to avoid. Ms Neild believes it is because of "lack of confidence in their knowledge and in the resources". She says:"For control to be at its best, it needs to be cross-curricular, linking to science (circuits), literacy - instruction writing is an easy link - citizenship, and Damp;T."
Working with a large group and having so much going on can be exhausting, but Ms Neild says the effort is well worth it if gives the lesson a "wow!"
factor - and getting that in such a difficult area of the curriculum is a considerable achievement.