Roy Lindsell always felt there were never enough questions in textbooks, so now he runs a business developing puzzles, games and other maths resources for secondary schools across the UK.
"My overall aim is to make things easier for the teacher," he says, "by making maths fun for the children, and relevant through things like sport."
Roy's resources include games he has developed such as Olympiad Maths, which turns the achievements of sporting heroes into maths calculations and conversions; Think of a Number, that reveals the mathematical qualities of 1 to 100; and Classic Puzzles, "four adventurers have to cross a rope bridge which will not take more than two people at a time, and anyone that crosses must use a torch which only has 17 minutes left in its battery."
You get the picture.
In 1989 Roy left his job as deputy headteacher of a school in Coventry after becoming disillusioned. But when he found that the alternative he had resorted to (running a shop in Whitchurch, Shropshire) didn't make much money, he returned to education, this time as a straight maths teacher.
"If you have energy and lots of ideas," says Roy, "being a teacher is not enough." So he tried selling the materials he had developed for his own maths classes and, encouraged when orders started to come in, left teaching for a second time in 2002, to devote himself to what is now a growing business, Pinnacle Education.
With a new product nearly every term, his materials have developed from the handful he started with - lesson starters, developing number skills, and tests and revision exercises - into the more complex puzzles that he offers today.
"Ever since I was a teenager I have been interested in puzzles," he admits.
"Some puzzles have a strange and magical element to their answers, and that always fascinates people - think of a number, double it, take away your birthday, you know the sort of thing - and others give children an ability to develop their logic, to think through and solve problems, and that's valuable in lots of situations in everyday life."
As well as new products - a poster about Andrew Wiles, Britain's esteemed but little-known mathematician, has become one of Roy's bestsellers - the energetic teacher has moved forward using new technology. Rather than just selling hard copies of his materials, he can also now supply them on disc.
"Teachers can have a licence to print however many copies they need, without the loss of colour that would result from photocopying," Roy explains. "And they can project the examples, from disc, straight onto whiteboards."
Meanwhile, Roy's partnership with a head of maths from Nottinghamshire, Chris du Feu, has developed a series of Sherlock Holmes-like investigations that can be used for the coursework that comprises 20 per cent of GCSEs.
Experiments with paper darts introduce children to aerodynamics; football results are used to find a formula for the number of possible scores at half-time and, nudging above GCSE level, a study of isoperimetric quotients reveals that a circle is the shape with the largest ratio of area to perimeter, which has implications for military strategists, historians and biologists, state the teacher notes.
Grant Whitaker, head of maths at Gayhurst School, Gerrards Cross, Buckinghamshire, says: "Pinnacle's resources are colourful and attractive, and great for stimulating thoughts and ideas." Particularly popular has been Zendal Trilogy, in which questions for 12 to 16-year-olds are woven into fantasy-come-adventure stories, such as Sorcerer's Quest, where solving a simultaneous equation is the only way to concoct a magic potion to free Princess Zendalene from the knights of the Dodecagon (12-sided) Table.
"Children really enjoy the game and get a lot out of it," says Jill Sherry, number two in the maths department at Queen Elizabeth School in Kirkby Lonsdale, Cumbria. "They learn a lot of skills such as problem-solving, communicating with each other and writing up their solutions."
lPinnacle Education Tel: 01948 664890 www.pinnacleeducation.co.uk