Picking the phone up and asking a company to support a school project is surprisingly easy, says Jim Monaghan, principal teacher of physics at Dalziel High, Motherwell. "I got a positive response from over half the firms I approached - I would explain who I was and what we were doing."
This would take time, because what the science department was doing - a project that all 180 first-year pupils could take part in - was novel and, with no external funding, challenging.
"We were keen to go ahead," he says, "because I knew how enthusiastic kids can get with a project that lets them develop their own ideas. I worked on an Arts across the Curriculum project, supported by the Scottish Arts Council, and am all in favour of kids learning science in different ways."
Getting all the first-year pupils involved in the Science Fayre took a bit of persuasion, he says. "It should be easier next year, because we have the P7s coming up later today and tomorrow. They'll see all these great projects and the prizes that are being won. So next year, when they're Dalziel High pupils, they will want to get involved with science themselves."
As the young PT chats about his project, its final phase noisily takes shape in the hall around him, with 50 finalists putting finishing touches to their creations. This is the first allotted school time on the mainly extra-curricular project, and pupils are making the most of it.
Lights are flashing. Wires and cables are being untangled and assembled. PowerPoint presentations are springing to life on laptops. Text and images are being attached to tall blue panels, lent by a local company.
Three girls are having trouble with their drawing-pins and are banging them in with their shoes. A lad suggests: "Use a glue-stick."
"Don't you dare," says physics teacher Margaret Craw. "Those panels have to go back."
"I just meant they could push the pins in with the glue-stick," he replies - whether that was his meaning or a ready response, as a small smile suggests.
"We asked them, in groups of two to four, to make something that showed an advance in science," says Ms Craw. "It was that broad. We offered a few ideas but most groups came up with their own."
Topics tackled ranged from guitars and gravity to black holes, the brain and the big bang theory. There were groups exploring technologies - satellite tracking, robots, rockets, solar energy - while others tackled issues such as global warming, power generation, health and the environment.
The youngsters looked at medicine. They researched cochlear implants, studied games consoles, electric cars, remote controls ... And, like all good scientists, they asked endless questions: How do fossils form? What makes things glow in the dark? Is there life on Mars?
The results of speculation and discussion, research and construction are slowly taking shape. Windmills whirr to generate electricity. Jumbled red and black balls in a box become, when assembled, the organic molecules of aspirin and paracetamol.
Waves ripple. Shapes glow. Model houses light up, radiating heat in all directions. The universe begins. "We thought we would do the big bang because it was a bit of a challenge," says William Prentice. On the table beside him, slices through space-time, as the early universe expands, are represented by diverging black shelves, with inlaid images, glowing red and white, of backlit spiral galaxies.
Nearby, a low-energy light bulb pops and Jenna Watters goes looking for a replacement, while Shannon Taylor explains how small choices make big differences. She indicates two infra-red images of houses, one all reds and oranges, while the other is mostly cool blue. "The red house has no insulation and uses normal bulbs," she says. "See all the heat that's escaping from it, especially through the roof. The blue one has been insulated properly."
Jenna explains what the images of Europe are: "That one shows which places will be under water when the seas rise. This is a picture of the world at night with all the lights on."
The contrast is interesting, with south-east England open to rising sea-levels and a big user of the main culprit - fossil-fuelled electricity.
Their project has been fun, say the girls, and its message is simple: people can make changes, reduce their carbon footprint and save money, all at the same time. It has changed them, Jenna says: "We found out how the world can be saved - before, we knew nothing about it."