AC method

Posted on March 25, 2022


Today peer tutors near close of day said “help! tomorrow we’re supposed to show the AC method and we don’t know it!”

Factoring is a task that — sorry, anti-memorization folks — goes so much better if you know your times tables. It is also something that easily waxes entirely procedural. Sorry, curriculum writers, forcing them through long division doesn’t help one whit. The factoring by one term does a little, sometimes.

It made me consider How I Explain It, and… I think I’ll make that a little video soon. (There was another thing — oh, that was chemistry! — about percent of molar mass and how there was a question of whether a mole of a thing that had some platinum in it was worth more or less than a mole of dimes. I had only overheard that little piece of obnoxiousness. They could have said “avogadro’s number” of dimes. A mole is *an amount of atoms,* not an amount. And when students are just getting the answer, they’re mostly going to miss it *if* your point was that anything times 10^32 is a whole lot. The students were perturbed that the explanation for the percent mass and molar mass were *not* explained in terms of “parts and whole.” YES — I’m going to need to tap Dorothea Steinke on that and say “great minds think alike!” Anyway, they also thought some visuals with molecules showing the parts and wholes would be helpful.)

(If I stick to distractions, mayhbe I’ll actually take notes and do the video; let me stick it on my Trello.) Riding home I contemplated talkin’ about how if coefficient is one, then those two last terms multiply to get the last term… but if it’s not, we need to work with both. And then you make a chart — and you put the desired product and sum on the chart! — the one peer tutor thought that was really important for “it’s right there!! It’s so much easier~!”

(and yes, as another tangent … I think we’ll discuss that his skills working with diverse learners are somethign he should be conscious of – because that could be a serious asset and make folks want to hire you if they’re an organization that grasps how many people these days are going to be diverse learners)

… so at *really* close to 5:00 they hollered over “it’s not workign for this one!!!” (and yes, they really meant, “come and show us…”) and I had explained that I usually did “guess and check” but IF that didn’t get me there quickly, said “OK JUST DO AC” and went through ALL THE COMBINATIONS and got there. A = 1, C = 60, B = -17. BUT 20 and 3 DID NOT WORK because they both needed to be negative. So … we walked through ALL THE COMBINATIONS and got to 12 and 5 😛

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