Can one just use the AREA MODEL willy nilly?

Sure, computing 37 x 21 via the area model makes perfectly good sense and there is good place for this general approach in early-grade maths.

But surely you can’t use the area model in upper-grade algebra too? Afterall (3x+7)(2x+1) is fine if x=10 (it is still 37 x21), but what if x is a negative number as is allowed in algebra? You can’t have negative side lengths and negative areas in geometry!

So what’s up with using the area model in upper-school math too?

Can one use the AREA MODEL willy nilly?


    QUADRATICS, Permutations and Combinations, EXPLODING DOTS, and more!

    Written for educators - and their students too! - this website, slowly growing, takes all the content Tanton has developed in his books, videos, and workshops, and organizes it into short, self-contained, and complete, curriculum units proving that mathematics, at all points of the school curriculum, can be joyous, fresh, innovative, rich, deep-thinking, and devoid of any rote doing! Let's teach generations of students to be self-reliant thinkers, willing to flail and to use their common sense to "nut their way" through challenges, to assess and judge results, and to adjust actions to find success. (Great life skills!)


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