Today’s opener was chosen for totally selfish reasons, which I will explain below. We’re starting our statistics unit today, so we’ll be a doing a lot of review of means, meadians, quatiles, and graphical displays – all with an eye towards interpretation. But only after I have students respond to a prompt for me:
What is a least common denominator (LCD)? Provide directions for finding an LCD to someone who may not know how to find one.
This Friday, I will be out of school for the Association of Math Teachers of New Jersey conference, where I am looking forward to participating in an Ignite session, hosted by my friends from the Drexel Math Forum. In these talks, a speaker has 5 minutes and 20 slides to share their idea – mine is on the importance of language skills in math classrooms.
So, today’s opener was entirely selfish, as I was looking for examples to share during the Ignite. The LCD problem is one I have given before during rational expressions units. – try it with your classes and watch the misconceptions fly! Responses to this prompt can often be pigeonholed:
THE “EXPLANATION BY EXAMPLE” CROWD
THE “NOT QUITE COMPLETE” CROWD
To be fair, I gave this prompt out of context, as fractions aren’t on our radar now. But it’s fascinating to see what built-in ideas students come to the high school with regarding a task they have now done for many years.