Today, we are investigating probability by trying to make 12 when adding two dice scores together. It is not an activity for teachers who are faint-hearted. The effects of children throwing dice while experiencing high levels of numerical frustration are not conducive to classroom peace. Last week, there was a set of soft-foam dice on the maths table. Now, I can find only hard plastic ones. I suspect the soft ones migrated to the parallel class doing a parallel investigation.

Dice are the ultimate weapon of maths disruption. Ten minutes in, and I am wondering what the probability is of going deaf before playtime. The noise of a large number of cubes clattering repeatedly on to hard table-tops is bad enough, but now there is Jordan wailing relentlessly from the other side of the room. He is resisting Brian’s attempt to steal his ear defenders. Brian believes that other children having property is theft and he feels it is his duty to liberate it.

It was recently suggested that, because of his particular condition, Jordan might benefit from wearing ear defenders. He has been known to get upset when noise reaches a level that means he can no longer hear himself talk out loud. Although, in fairness, I’ve always found him good at ignoring distractions. He once ignored my pleas to stop singing the six times-table song for the best part of a fortnight.

Originally, Jordan’s ear defenders were to be worn only for noisy activities such as eating lunch in the dining room, singing in the hall and mindfulness sessions in the classroom.

Bright red and customised

Unfortunately, this plan didn’t take into account the fact that he might enjoy wearing them and be resistant to taking them off. I suspect this is partly because they are bright red and have been customised with his favourite dinosaur stickers. One side has a stegosaurus on it, the other side a pair of pteranodons.

Initially, there was some concern that Jordan wearing ear defenders might cause other children to make fun of him, but the opposite has been true. A number of children are envious of them. Ear defenders are suddenly the latest thing in designer headwear and the must-have accessory for every fashion-conscious student in this class.

Consequently, discovering all of hexagon table wearing a pair would not have been surprising if the probability of this had not been zero. Jordan has the only pair and he’s extremely averse to sharing them. On closer inspection, I discover that the children are not wearing ear defenders at all, but sets of headphones appropriated from the book corner listening centre.

Before I can decide whether this is a fashion statement or a reaction to extreme noise, Jordan arrives with the results. After 100 throws, he has found that the probability of throwing 12 is only three out of 100. He tells me seven is the most likely score, with 18 out of 100. I give him a Maths Genius sticker and make a mental note to order a class set of ear defenders - plus a pair for me.

Steve Eddison teaches at Arbourthorne Community Primary School in Sheffield