Jamie was rhyming drum with thumb, while Matthew was doubling, halving, and learning his multiples of five.
Sheffield's literacy and numeracy summer schools were in full swing, and local MP David Blunkett - who just happens to be Secretary of State for Education - had popped in to see how his Government's initiative was faring in three of them and convince the 11-year-olds that knowing times-tables is vital.
The example he chose was that of his former deputy Stephen Byers - now a Treasury minister - who famously claimed that seven eights were 54 during a radio interview.
"He's never going to be allowed to forget it," said Mr Blunkett, revealing how he had stalled for time when posed a similar question.
This year is the first for national numeracy summer schools - such as that at Yewlands in Sheffield -and the second for literacy. The intention is to boost the skills of pupils falling just short of expected levels before starting at secondary. Each school gets #163;10,000 of Government money.
Kam Grewal-Joy, of Sheffield's advisory and inspection team, is a scheme co-ordinator at Yewlands. She said: "We wanted level 3 children who we felt needed a boost in confidence and who would respond positively."
While a few had to be rounded up on Monday, when the school started, Ms Grewal-Joy says many arrive half an hour early.
"It's good fun," said Matthew. "I am learning lots of things and making new friends and I am getting to know Yewlands where I start in September."
The children do a 10 to 15-minute rota of oral and mental number work,use the interactive maths programme Success Maker on the computer, and do other tasks including number games.
At least one session daily is outdoors, for example, scoring in tennis. Ms Grewal-Joy said: "There is a high number of underachievers in this area from disadvantaged backgrounds. Fewer than half will be at the required level in numeracy when they join secondary school."
The inspection team will use its experiences to write an information pack for future numeracy summer schools.
Mr Blunkett was impressed, saying: "The schools can switch kids on to maths and can use a mixture of methods - through playing games and using computers - to engage them in ways that can also be used in normal term-time."
Mr Blunkett wants to see a substantial expansion next year of the 562 literacy and 51 numeracy schools.
He said: "We need to get different groups of people involved in bringing activities to schools during holiday time and evening, and not just heads and teachers who are making a heavy commitment at a time when they would normally be having a break."