More than half the class got this wrong. Can you believe it? I couldn't, so I tried to imagine what had been going through their 14-year-old minds.
Well, first there's all them words. I must decode shape, angle, right, parallel, equal. Then I picture four of one thing, four of something else and try to see them in relation to each other. What's two pairs? Is that four? OK, now what was I thinking of when I started this question? I can't hold it all in my mind! It's the language - not the maths - that's perplexing. Is English comprehension being examined too? After the test, I said, "Draw and label a square," and they did it instantly.
The test question would have been fine in a quiz, because a conundrum is the sort of tease we expect. But Year 9 were annoyed and depressed by it.
They wanted self-confidence, not prizes.
Inappropriate questions are a recurring hazard for supply teachers. The work set often looks as if it is straining to "raise standards" while ignoring the pupils.
Earlier, I covered a Year 10 history lesson. As I walk in, Tom jumps off a desk. Sharon, painting her nails, is in the middle of a rant about her boyfriend. Daniel pulls his woolly hat over his eyes and his anorak over his chin. I find the set work on the desk - and my heart sinks. They have to write an essay on the Treaty of Versailles explaining how far Woodrow Wilson and George Clemenceau achieved their respective aims. I look up. Tom is talking about a friend of his who set fire to his primary school. It's fascinating.
"Can we link that story with the First World War?" I ask.
"I can't do this," someone wails. "History's boring!"
"If we read through chapter three, we'll find bits that'll help with the essay," I say. The written work that follows is at best accurate copying.
They do not even know the dates of the First World War. We have gone through the motions of raising standards by trivialising a complex subject.
In another part of the school, however, a revolution is taking place.
Year 7 are studying learning styles. They are discovering the terms visual, auditory and kinaesthetic and describing their own preferred ways of learning. Howard Gardner's theory of multiple intelligences is releasing them from a narrow concept of IQ to celebrate their individuality. I have covered a couple of learning styles lessons and found children of all types to be enthusiastic and focused. The subject plays to an adolescent strength: what Gardner calls "intrapersonal" intelligence. A kind of synthesis is achieved between the learner and the subject, in contrast to the clash of civilisations in the history lesson.
Multiple intelligence theory emphasises how different we all are as learners. If, in the history lesson, the students had been given some choice over what they learnt about the First World War, then motivation and results might have improved.
So next week for maffs, Year 9 will design gardens. They may use percentages, fractions and geometry, but each child will choose how much of this abstract work applies to his or her creation. The teacher-directed approach just isn't working any more.
Philip Hume is a supply teacher. He writes under a pseudonym