Using Diagnostic Questions in Maths

We were lucky to have Craig Barton visit our school last week. He introduced a wonderful and simple diagnostic tool, Diagnostic Questions. At the start of a lesson a teacher can quickly diagnose misconceptions and address them easily.

This is an example of how it works:

In my Grade 4 class I was re-introducing squared numbers  (last seen in Grade 3). I wanted to know who remembered the written format and who had misconceptions.

I showed the following slide:

Square Root Diagnostic Question

The students voted on the answer they thought was best. They needed to be prepared to explain their answer.

After the vote, I asked one representative from each answer to explain their thinking. Everyone heard each others’ explanation. (The teacher has no reaction.)

Spot the misconceptions!

10 – “Because 5 x 2 =10” (misconception: the squared sign is seen as “times 2”)

7 – “Because 5 + 2 = 7” (misconception: add the 5 and the 2)

25 – “Because 5 x 5 = 25” (these students understand the squared sign)

52 – “Because the ‘2’ was just written small” (misconception: superscript has no meaning in Maths)

Once all answers had been explained, we re-voted. By listening to each other, most students changed their vote to the correct answer. They were either reminded of the concept of squared numbers or they were convinced by a classmate.

The correct answer was discussed and a few examples given. As a teacher, I was now confident that my students would go into their Maths inquiries of squared numbers with no misconceptions. It is a very powerful tool.

Talk less. Ask more. (Taken from Kath Murdoch’s blog titled “How do inquiry teachers….teach?” I recommend it.)


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