Lesson Plan #:AELP-ALG0002
Submitted by: Gus Sorbo
Endorsed by: Dr. Don E. Descy
School/University/Affiliation: Mankato State University Date: June 3, 1997
Grade Level(s): 8, 9, 10
Description: The FOIL method is an easy way to remember how to multiply binomials.
Objectives: Given two binomials, students will be able to multiply the correct terms of the binomial together and be able to combine the two binomials into a single polynomial.
Prerequisties: Previous knowledge of multiplying variables and coefficients is assumed.
Concepts: The word FOIL is simply an acronym for the method of multiplying
binomials. It stands for:
F irst (multiply the first term of each binomial together)
O uter (multiply the two outside terms together)
I nner (multiply the two inside terms together)
L ast (multiply the last term of each binomial together)
For instance, let’s look at (x 2 +3)(x-2)
F irst (x 2 )(x)=x 3
O uter (x 2 )(-2)=-2x 2
I nner (3)(x)=3x
L ast (3)(-2)=-6
Now that we have all the terms, we can add them together in descending
order of the power of the variable. Then we get:
(x 2 +3)(x-2)=x 3 -2x 2 +3x-6
There, we have multiplied the two binomials into a polynomial. Using the
FOIL method, students will be more likely to remember how to multiply
binomials, and as a result, show a better understanding of the subject.
Assessment: In their math journals, have students explain the directions to the FOIL method.