A secondary teacher friend of mine was showing her sixth-formers a DVD to start a lesson the day Ofsted visited. (Not real Ofsted - one of those fake, practice Ofsteds headteachers pay for instead of spending the money on something useful like pencils and paper.)

In her feedback, the smart-suited adviser who watched her lesson criticised her for showing the film in its entirety, because “the pupils can’t concentrate for 20 minutes”. Apparently, 17- and 18-year-olds need their 20-minute film shown in blocks of four minutes with breaks for discussion in between. Let’s hope they find themselves in those universities where lectures are given in blocks of four minutes, or in a job where you change activity every five minutes rather than spending eight hours a day shelf stacking or gazing at a computer screen.

Nowadays it’s common knowledge that pupils 50 years ago could consume War and Peace in one sitting while this generation struggle to get through an advert without switching channels. So how do you teach to the attention span of generation X? Obviously you can’t talk at them - you’d lose your kinaesthetic learners in one fell swoop. Show them a film? If it’s not got any fight scenes in it, what’s the point?

Apparently we should be thinking outside the box, finding new ways to grab the attention of the eternally overstimulated. Sadly, I’m a teacher, not a Blue Peter presenter. I don’t want to zipwire into the classroom, equip all the kids with 3D glasses and teach percentages as a character in Call of Duty 3. I quite like just telling them things, showing them things, asking them to tell me things in return, maybe even writing them down.

I read somewhere that girls are supposed to have a better attention span than boys. I think this is probably true because when I was explaining it to my husband he drifted off halfway through because England got a wicket.

But for exactly how long can you expect children to concentrate on something before you lose them? I was told on a course that children under 11 can concentrate for only as long as their age in minutes, plus one minute. As a theory, I quite like this, but I’m not sure they should cap the age at 11. Maybe nobody should be made to concentrate on anything for longer than their age plus a minute. Fresh-faced NQTs would vacate staff meetings well before half an hour is up and could be on to their second pint before their retirement-nudging colleagues get to join them. Cinemas would sell you tickets only to certain films and nobody would be allowed to watch Gone with the Wind.

Recently, though, I’ve noticed lots of my children breaking these rules. They read whole books (apparently you can now get a GCSE in English literature without having to do this). They write for prolonged lengths of time. They listen to me bang on about ancient Greece and actually remember what I’ve said a week later.

Obviously, they’re not all like this. There are children in our school who could be taught by a tap-dancing Wayne Rooney surrounded by a troop of flag-waving giraffes and after half a minute they’d still be carving initials on their ruler and aiming rubbers at their classmate’s head.

But to base your whole teaching style around the needs of these children is as flawed as the theory that children are disruptive in class because the work isn’t engaging enough. Classrooms are now full of colour, sound effects and interactive whiteboards showing 27 ways to animate long division and still the only time you can get every child looking in the same direction is when the door opens.

Maybe we should give the kids more chances to exercise their concentration skills. Next week I’m thinking of reading them a whole book. We might even have a stab at Gone with the Wind.

Lucy Edkins is a primary teacher in Nottingham.