Keep the FOIL in the Kitchen

   Last year I taught my kids the “FOIL” method as a cute trick to help them multiply two binomials: (x+2) (x+4). FOIL stands for first, outer, inner, and last.  Looking back, my rational was twofold: I learned the FOIL method from my algebra teacher, and my kids had learned the FOIL method in pre-algebra.

 

This year, thanks to an article posted on this blog, “Nix the Tricks,” I took a new approach. Instead of using FOIL, I told my students they had two terms to distribute when they multiplied binomials.  For example, (x+2)(x+4), my kids distributed x to (x+4), then 2 to (x+4), and finally combined like terms.

 

There were multiple benefits for my classroom; we had already discussed the distributive property, my kids didn’t need to remember a meaningless trick, and they were able to explain why and how they could multiply various binomials and polynomials. Most importantly, everyone caught on quickly, which allowed for self-exploration by the students into larger polynomial multiplication, such as a binomial multiplied by a trinomial. 

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