john weisenfeld

…is probably looking like an unfortunate name for adding monomials when you see a mistake like this one. Right?

Or wrong? Speak up in the comments. And more thanks to John Weisenfeld for the mistake.


  • The writing makes it ambiguous. That could be 30x^544 or it could be 30x^5^4^4.

    (I’d sort of hope for the latter, because just mashing the digits into a 3-digit number is a scary-weird mistake to make at that level.)

  • I suspect the student wasn’t assigning any meaning to the process. Stuff that was up there stayed up there, and the stuff was put together.

  • Distributive property! Maybe it would help if we talked about the distributive property instead of the much vaguer-sounding “like terms”. After all, that’s the property that allows us to do the combining and tells us when things are “like terms”.

    On the other hand writing 12x^5 + 10x^4 + 8x^4 = 12x^5 + (10+8)*x^4 = 12x^5 + 18x^4 gets kinda long. We’d have to wean them eventually.

    On the third hand maybe doing a lot of this would help them when it came time to factor things.