What marks it out, of course, is the fact that Jo, Rebecca and Chris have long since left primary school. Now they are in the second year of a teacher-training course at Bishop Grosseteste College in Lincoln. In a few weeks' time they will try out their games on some real pupils and will write essays on whether they met their aims.
"It's extending the children, rather than time-filling," Chris explains. "It isn't arithmetic but it's arithmetical thinking. It's a way of making the children think more logically."
Students here have little time for Gillian Shephard's planned reform of teacher training, which is partly aimed at squeezing out the child- centred teaching methods they are learning. Every pupil is an individual, they argue, and this kind of lesson caters for differing needs as well as being great fun.
In a recent teaching practice session Peter Wilkes, a fourth-year student, gave all his pupils Argos catalogues and asked them to decide what they would like to buy if they had pounds 50 to spend. It was basic arithmetic, he says, but the children enjoyed it far more than they would have done if he had simply stood at the front and lectured.
Peter says he uses a great deal of the "whole class" teaching that ministers and advisers want to see increased, but it is interspersed with group sessions and is filled with chances for the children to participate.
This college is regarded as one of England's finest. The schools inspection body, Ofsted, visited a year ago and was impressed. The maths in particular was said to be very good, and students learned a wide range of professional skills. English was good too, though the students' knowledge and understanding of language was sometimes deficient.
The principal, Professor Leonard Marsh, says it turns out teachers who can employ both traditional and modern methods. But the image of teacher training institutions as bastions of 1960s liberalism remains, and sometimes puts him at a disadvantage. "People expect me to have sandals, long hair, two earrings and a nose ring. Instead, I have a multiplication table chart," he says.Reuse content