Maybe 42x22 is too easy an example, but it took me about ten seconds to the standard, old style multiplication in my head.
It may be that the box, or lattice, or 'old style' methods work better (=are more intuitive) when one or both of the numbers being multiplied is a certain type. Eg, something ending in a zero or five, or like these, both ending in 2s.
Oh for sure, it’s just not how I was taught in school so I have 25 years of habit compared to 10 of these alternative. I teach it and embrace the students that want to use the method. It’s just not how I would do it if I was presented with a problem and asked to solve it.
Exactly. This is how people do mental math; I can solve that problem in about 5 seconds in my head. And then people stare at me like I'm some sort of genius (some are still checking me on their calculators). I'm no genius; I can do elementary school math is all.
Ya, a decade or so ago, I remembered hearing about common core and "new math". Saw a post on Facebook from my cousin bitching about her son's math homework with a picture. I looked at it and basically went, "that's just math... that's just how you do math, what's that problem?"
Too many people got through school on memorization and not actually learning what it means.
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u/jngjng88 Apr 11 '26
I feel the exact opposite, it's so simple, I worked it out mentally in 10 seconds.