9 Comments

But...it's not 4. In the absence of parentheses, you do multiplication and division before you do addition and subtraction, so it's (2x8)-(4/3) = 16-1.333333 = 14.666667

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Agreed. Good ol’ Please Excuse My Dear Aunt Sally (parentheses, exponents, multiplication & division, addition & subtraction).

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I guess Grace was doing it (2x8-4)/3

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So a lot of people intuitively approach math this way, and this is kind of how they teach it now (via the much-maligned common core) and I firmly believe that if I had been taught this way - some actually processes and rigor around the intuitive approach - I might be able to do math now.

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Yes! The whole "show your work!! and it better be the RIGHT kind of work" thing was my downfall, and I gave up in disgust circa 8th grade. This way of doing it served me extremely well when I was a cashier, though, and I can make change like nobody's business. So maybe common core is onto something after all.

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Saaaame. The idea behind common core math is to start off teaching kids that there are many ways to do math, so even on basic addition, they're learning four or five ways to get to the right answer. Also, the way Danny describes breaking down a problem (34+52, well, 30+50 is 80, and 4+2 is 6, so 86) is not just intuitive, it helps you to see that numbers have components, and that you can manipulate those components in many ways, and learning how to break a math problem down to its components is really important to higher math, which they just kind of sprang on kids when I was growing up, after six or so years of teaching us that math was rigid and could only be done one way. T

The other thing common core is big on is teaching kids to have what they call "number sense," which is just kind of a feeling about how numbers fit together -- which is like Danny saying, I know that 4x8 is 28 and work backwards from there to find 4x27.

As you can tell, I have strong feelings about common core having gotten a bad reputation. :) And at any rate, if there is one hill Americans absolutely do not need to die on, it would be the idea that the way we were taught math worked.

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Danny, I just want you to know I do arithmetic in *exactly* this way and I went on to get a degree in architecture from a university that prides itself on forcing all its architecture students to take the same essential engineering courses as the actual _engineering majors_ for the first three years.

What I am saying is, you could be an engineer with these maths.

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TBH, this is exactly what I thought being married to a teacher would be like as a kid.

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17x15 stumped me, I must say. I did 5x7 which is of course 35, as previously discussed, then did 10x10, but twice because... there's two of them? Anyway that's 200 so 200+35 = 235. I do not know where they other 25 went.

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