The tall, strapping 15-year-old swaggered into class, put his feet on the desk and plonked down a can of Red Bull. He was not in the mood for maths.
But out of confrontation comes opportunity, believes Michael Steer, the maths teacher and depute head who shot to fame last year in Channel 4 documentary Educating Yorkshire.
He set the Red Bull drinker a challenge - to work out how much of the energy drink it would take to fill the Earth. Suddenly, the boy showed a previously unseen enthusiasm for maths - and came back with the right answer.
"What works can be completely different from kid to kid, but what you always have to do is build a relationship and find something to get them onside," Mr Steer told TESS, prior to addressing a maths conference in Glasgow held to help teachers turn sceptical teenagers on to the subject.
"It's not about eureka moments but a gradual chipping away," he said. "Really what I should have done with that boy was confiscate the Red Bull, but he was looking for that. Just sitting around and having a laugh is important - supporting kids, not shouting and telling them off."
Mr Steer's experiences at Thornhill Community Academy - teaching classes of up to 36 often disaffected students - informed his talk at Easy as 123: Making Numeracy and Maths Count in Scotland, organised by charity Children in Scotland.
"They tend to have this belief that maths is some sort of mythical set of skills accessible only to a few," he said. "If you're good with figures, it's almost like you're part of a travelling freak show. It's a bit of a bogey subject, and not just with kids - a lot of staff are like that, too."
But Mr Steer had witnessed a very different attitude on the part of his four-year-old daughter and her classmates, he said. "They love maths, but somewhere along the line they get to an age where a significant number hate the subject."
He argued that secondary maths should be more fun but recognised that there was sometimes no getting round the dry learning required for exams. For that, he liked to adopt a conspiratorial approach.
"There's a level of honesty required sometimes," Mr Steer said. "Things like trigonometry and vectors - these are not skills needed by kids day in, day out.
"If I'm asked why something is relevant, my answer might be something like: `When you leave school you will be stopped every day by someone who will run up to you at great speed and tell you that you have to plot some points to save the president's life.' There's a shared acknowledgement that you might not see the relevance - but you will get a qualification that you'll carry through life."
As Educating Yorkshire continued to garner praise - it is up for a National Television Award on Wednesday - Mr Steer explained how the documentary series had sparked "a real buzz around the school and pride among the kids".
Viewers were astonished by Mr Steer's devotion to helping his students get their all-important C grade at GCSE, ignoring painful skin allergies so that he could support them through their exams. The young people were impressed too, it seems.
"Their view of us now isn't so much: `There's that fella that talks to us five times a week about maths'," Mr Steer said. "They see the amount of care and commitment that goes on out of class hours. `We had no idea how hard you worked,' they say."
The new-found celebrity of their teachers has also been a matter of comment for the students. "They'll tell me matter-of-factly, `I saw you on Pointless Celebrities'. I say, `Yep', and that's it," Mr Steer said.
But such has been the demand for Mr Steer and his Thornhill colleagues to appear on various television and radio programmes that they have not been able to find time for them all. "I had to turn down (Jeremy) Paxman," said Mr Steer, who was too busy even to go on the BBC's flagship current affairs programme Newsnight.