Critical ThinkingPrimary Education

About those viral Common Core problems

If you’re anything like me, you’ve probably seen one of those viral posts on social media presenting a (seemingly) ridiculous common core math problem, and possibly even a frustrated parent responding with some kind of exasperated takedown.

Like this one. (Also pictured)

It is super tempting, especially for those of us who have never seen anything like the given problem, to sympathise with the parent. But there is (shockingly) a method to all of this, and it lies in providing students with multiple correct methods for doing the same process. After all, just because the (one) way we learned to do a certain kind of problem in elementary school might be the most efficient (for us), that doesn’t mean there won’t be students who can wrap their brains around things better by using an alternate approach.

In fact, I quickly realised that I do this all the time when teaching basic music theory: there are usually several ways to look at the same operation, and students are always better off hearing several.

Anyway, here is a good article explaining things from a math teacher’s point of view.

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Dan holds a PhD in Music History from a major Canadian university and is now pursuing a M.Ed in Higher Education at another one, because he likes to collect very expensive paper. He performs stand-up comedy at venues all over Toronto when he's not busy playing JRPGs with his cat, Roy. You can follow him at @incontrariomotu, but he isn't going anywhere. You can also send him a tip on PayPal ( if you like his work!


  1. February 8, 2015 at 9:57 am —

    Seriously, it bugs me when I see these memes like “look at the crazy way kids are doing math these days!! back in my day, I did it this way!” But if anyone takes a second to think about how you do mental math, the common core method is the one that we use. I think a lot of the resistance to common core math (besides the fact that teachers and parents may be ill-prepared for now) has to do with the fact that people are resistant to change the older that they get.

  2. February 8, 2015 at 7:27 pm —

    Part of the problem is that they chose a question for which the standard method is faster and simpler. Compare this one with 10000 – 1111, or 12345 – 3456 and the method demonstrated seems a lot more sensible!

  3. February 12, 2015 at 11:55 am —

    The question is supposed to make pupils THINK, helping them to better understand what happened, helping them to develop skills for solving mathematical problems.
    Fucking amazing, if you ask me.
    There are many ways to get a result. My kid uses a similar method, though they haven’t arrived at hundreds yet. 75-37 is done in several steps. Weaker students can add a third step for getting the “going under 10” right. My kid simply does it in her head and writes the number in one single step. The important thing is that her teacher happily accepts either way as long as children reliably get the right results. I consider it my job to give children tools. When they show they can use them correctly, they can choose from their toolbox what they think is best for them.

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