Thursday, August 28, 2014

A Brief Look at Phrasing Descriptions of Functions

During a lesson this morning, students were asked to describe this function rule in their own words:


One student came up with this:


We had a brief group discussion about whether this phrase made sense or not. One student said that they might interpret this phrase differently:


Some students agreed, saying that the wording could possibly suggest that the sum was performed first, and then squared after. I asked them to think of a better way to say what was trying to be said, and they came up with this:


Not terribly different, but the order of the words made a lot of difference. The students agreed that this phrasing was clearer than the original.

Admittedly, this was a pretty simple problem, but the students brought up some good points in our conversation around it. It was a good opportunity to explore the nuances of being precise when talking about mathematics. Even one turn of phrase can be misleading; hopefully the students learned a bit about being careful about their wording while still being succinct.


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