Our Primary teacher, Ms Hewitt:
In theory she knew how to do it,
But as often as not
When she felt on the spot
She just made it all up. And we knew it.

Teachers should take care not to underestimate pupils’ insight and cunning. Admit it, if you’re flustered: it’s a good deal more endearing – and educative – than any amount of nervously-extemporised drivel.