After a few minutes a boy comes up to my desk with a blank piece of paper. "Are you stuck for ideas?" I ask him.
"Oh no, I've got plenty of ideas, Sir, I just wanted your autograph.
"Why would you want that then?" I enquire.
"Well, you might not be here tomorrow."
I can't argue with that and give him my signature.
Tuesday: I'm working in a different junior school with ten-year-olds. We are reviewing solid shapes for our maths lesson so I begin by asking them the names of any three dimensional shapes they can remember. "A jail," one girl calls out from the back of the room.
I question her but she insists she's correct until someone finds the box of shapes and we realise she is referring to a prism.
Wednesday: A Year 9 English lesson in a boys' school. I soon realise that adolescent youths are not as enthusiastic about creative writing as Year 4 pupils.
The weather is suddenly grey and stormy - the wind is whipping across the playing fields outside and an idea for some poetry stimulus comes into my head. Shortly afterwards I overhear a conversation at a desk by the window as one of the boys nudges his friend.
"Hey, look. It's lightning."
"I know. Keep your voice down or he'll make us write about it."
Thursday: Five and six-year-olds in today. Infant children really are amazing. They take so long to button up their coats or get changed for PE and yet they finish any piece of work I set them in world record time.
I notice from the register that one child has just returned from holiday.
"Where did you go, Emma?" I ask.
"Oh, that's nice. Did you go to your relatives?" "No, I stayed with my Gran and Grandad."
Later on during the day the subject of the Vikings comes up and I explain that one of the first places they travelled to was Iceland. There are some puzzled looks at this. One of the boys puts his hand up.
"Yes, David?" "Sir, why would they want to go to a frozen food shop?" I decide that I am probably not cut out for any long-term infant teaching.
Friday: As the headteacher leads me to my top junior class, she utters the chilling words: "There are some nice children in this class, but some of them do need firm handling, particularly Darren."
As we cross the hall I notice a plaque on the wall dedicated to those from a previous time who have fallen in the line of duty. I wonder whether the names of other Year 6 supply teachers have been added to this list.
The headteacher is right. Throughout the day Darren is like a pot that is ready to boil over, but somehow I manage to keep him on "simmer" mode.
I am greatly relieved (and exhausted) when the bell signals the end of school, but I anticipate a confrontational end to the week as Darren approaches my desk.
"Are you here next week?" he enquires. Did I detect a note of menace in his voice?
"No, Darren. Your teacher should be back on Monday." I wait suspiciously for his next move.
"Oh well, thanks for teaching us, Sir. You're OK really."
Tim Parkes is a supply teacher living in Birmingham