Thursday, November 6, 2014

Deconstructing Common Core

[A quick note: there's been some confusion over over exactly what constitutes Common Core, I might dig deeper into the question at a later date, but for this post, we'll be talking about materials released under the Common Core banner.]

I volunteer a couple of times a week to help a group that tutors kids from urban schools. My role is designated math guy. I go from table to table helping kids with the more challenging homework problems.

Recently, I have noticed a pattern in helping with Common Core problems. First I explained them to the students, then I explained them to the tutors.

That may be the most noticeable difference between the mathematics of Common Core and the new math of the 60s. In the summer of love, an advanced degree in mathematics or engineering was sufficient to understand an elementary school student's homework. These days, the tutors with math backgrounds often find themselves more confused than their less analytic counterparts since what they know about solving the problem seems to have nothing to do with what the assignment asks for.

To follow a Common Core worksheet, you really need to have a little knowledge of the underlying pedagogical theories. Unfortunately, if you have more than a little knowledge, you'll find these worksheets extraordinarily annoying because, to put it bluntly, much of what you see was produced by people who had a very weak grasp of the underlying concepts.

I'm starting a thread called "Fixing Common Core."  I'm going to take some problems that are associated with Common Core and try to explain both what the authors were trying to do and how they could have done better with a different approach. The posts almost certainly won't live up to the title but they will, hopefully, shed some light on the topic.

I'll be back early next week with a discussion of the following:


  1. Is it a strategy that we (in NZ) would call "tidy numbers"?

    7 * 3 = (10 - 3) * 3 = 10 * 3 - 3 * 3 = 30 - 9 = 21

    It's a "do it in your head" strategy and the kids would typically do it with much larger operands e.g. 98*7

    1. That's actually one of the points I'm making in the follow-up, that this is a valid approach badly mishandled. I even use a similar example -- 98*3.