Sustained Shared Unthinking - the Case Against Maths Sets

28th November 2015

We are, as a profession, optimistic. Otherwise we couldn’t carry on. Sometimes this leads to a triumph of hope over experience. Painfully.

In a lesson on angles I decided to throw in a quick number challenge, as in dividing a right angle and asking, “What’s half of 90?”
Didier: Easy it's 99.
Me: Try again, it needs to be smaller.
Didier:10
Zahra: 40
Me:  OK - show me how.
(Zahra shakes her head)
Andre: 50
Binh: No 50 is 100
Me: Are you reminding everyone that 50 is half one hundred?
Binh: No
Didier: I do think its 99
Me: OK lets draw a line. Can you see – maybe we want to look at the tens on each side,
What’s the 10 before 90
Amy: 100
Me: Close, that’s the ten after what’s the ten before?
Didier : 99
Me: The tens number
Amy: 80
Me: what’s half of 80
Zahra: 40
Me: Fantastic (writing on board) is that the end answer though? What about this ten? What’s half of ten?
Amy: 20
Me: Wrong way. Victoria what’s half of 10?
Didier: 1
Victoria: (looks at 100 square and says questioningly) is it 5?
Me: Yes it is. OK what’s 40 add 5?
David: 45
Binh: Exactly!

You can well imagine the thoughts in my head as this went on!

The problem with a group like this is that everything is tentative and they are so easily led into changing their line of thought.
They lack confidence in what they know, they are trying to please me and guess what I want. They assume questioning means they are wrong. They use strategies such as guessing or repeatedly saying the same answer. They lead each other astray.
In a more mixed group the discussion could happen without the scary query from a teacher, they could help each other.

So on balance I would say ideally, don’t set, but do create safe spaces for questioning and experimenting.

Where I am we do set, so on and up I go. 99.