Why your shirts don’t fit

If you're a human man and you wear shirts (an intersection of descriptors that I suspect describes about half of you), you may have noted that the armholes are often kind of big. "Huh," you may have said. "These armholes -- they're big."

The reason that this is the case is that our bodies are all shaped differently, and for a given neck measurement and sleeve length, arms are located at different heights and of different circumferences. In order to make the shirt fit as many people as possible, manufacturers simply make the armholes bigger. As a result, they fit some people perfectly, and they fit most people OK. But they never look quite as good as if the shirt were made just for you -- there's extra fabric hanging there under your arms, and the proportions are functional, but not necessarily flattering.

Math instruction is the same way: schools need to teach a lot of students, and they need to do it efficiently in terms of dollars-per-student. Everyone uses the same book, and sits in the same classroom, listening to the same teacher and doing the same practice problems regardless of whether those things are connecting to them, in particular, as learners.

(For what it's worth, this non-personalization is exacerbated if you're in a state like Maine. Because textbook publishers are also making their armholes too big, they are much more concerned with fitting to the standards established by large states like Texas and Florida than they are with meeting the needs of lower-population markets.)

(If you're saying, 'How much can that possibly matter -- math is math!', I have suspicions about how well your shirts fit.)

This is one reason that many people can struggle with math: because the approaches they're presented with aren't directed at them, they're directed at the most people possible -- but that group isn't even that large, and anyway, who cares how many people an approach does work for if it doesn't work for you?

The world is full of people, and schools full of learners, who think they're not good at math when really, they just need a shirt that fits slightly differently than the one that they were handed as part of the uniform. This isn't something they did, and it's honestly a terrible shame because of how enjoyable and how useful many of these topics are.

Measurements

We’re getting acoustic inserts for our bedroom windows — we’re on Main St in Rockland, which is lovely but can be noisy.

For each window, there are six measurements done with a laser ruler, and which we’re doing multiple times and comparing via a third Google Sheet coded to visually highlight large variances that might suggest a need to re-measure. We’re dealing with data, doing unit conversions, figuring out the most user-friendly way to record measurements down to 1/32″, designing tables, determining tolerances, computing ratios, and a million other mathematical things.

When I say that we should be teaching math by including learners in things that are real, collaborative, multi-step and of actual use, this is what I’m talking about. People fixated on tests and word problems and abstraction and so-called ‘loss of rigor’ need to explain why anything they’re talking about is worth teaching to every single American student.

I don’t have that burden because I’m starting from productive engagement with the world, and suggesting that we should be teaching (primarily and first) the skills necessary for that type of engagement.