it's 9am on a frosty February day and a class of nine-year-olds sits with furrowed brows. They are trying to answer a question: How much water did you use yesterday? They have just walked the 10 minutes from their primary school, Bushey Heath, near Watford in Hertfordshire, to the Clay Lane Environment Centre; soon they are ready to answer Barbara Rowbottom, the centre's education officer.
Most had brushed their teeth: that was a litre gone. What about the scrub for the filthy football kit in the washing machine yesterday? A few hands went up - this time it was a whole 100 litres.
When they had filled in a table with headings such as drinking, toilet flushes, washing up and dishwasher, the pupils totted up their water usage.
Some, usually keen footballers, had racked up totals in the 400s, but even the frugal had used 200-plus.
Now came the satisfying part. A laptop linked to a whiteboard was in the middle of the room. The pupils filed up and, with fairly minimal help, tapped in their initials and their personal total of litres. A large coloured bar would appear on the screen, ripe for comparison with the other pupils' differently coloured bars.
They were using software from 2Simple, the Junior Video Toolkit. This, along with the KS1 version, is already in more than10,000 primary schools.
The package allows children to paint, publish, count, make graphs, move shapes around the screen and create simple branching databases. (The kits have now been followed by 2Investigate, demonstrated briefly later in the session).
The application at the environment centre involved group use, but both Toolkits encourage independent handling, too. The Junior Toolkit and 2Investigate feature "intelligent intervention": if a pupil is uncertain how to use a program, the software will detect the difficulty and offer a short, helpful video. Both kits also offer lesson ideas in video packages.
This was the first time class teacher Allison Scarth had seen the Toolkits in action. Her verdict? "The immediate results it gives make things more exciting for the children. We could have done it manually but it would have taken much longer." After a break outside, the pupils came back for a second session, on animal classification. First, a branching diagram showing different groups of animals was projected on to the whiteboard.
Then a series of questions, such as "Can you fly?", separated them into groups - mice, newts, foxes, snails, slugs, woodpeckers, frogs and ducks.
Next, the children were given cards with pictures of "their" animals, and a key with the animals at the bottom but with the questions needed to arrive at the classification left blank.
Jo Moulin, senior education officer, has been at the centre for five years and she is delighted with the 2Simple software, which has been used for two terms. "It's so instant - it's exactly what you need. And children tend to take more seriously the business of working out their figures accurately - after all, they are going to be on public display."
Clay Lane Environmental Centre is at the Three Valleys water treatment works at Bushey in Hertfordshire. National curriculum-linked activities geared towards key stages 1 and 2 are available year-round. The centre can be booked for hourly sessions, while a full day of activities costs pound;2.50 per child. Contact 020 420 5864; firstname.lastname@example.org