Factoring Trinomials: Differences of Squares

Lesson Procedure:

Print the classroom lesson plan and worksheet questions (see below).

Lesson Excerpt:

Factoring Squares and Differences of Squares

- “Today we are going to expand on the work that we have been doing. We are going to learn how to factor what we can ‘Squares or difference of squares.’ Here is an example.”
- On Board: x2 – 25
- “Let’s look at this problem. What is the first thing that you notice about this problem compared with the other ones we have been factoring?”
- Student answer- there is no middle term.
- Note: If the students don’t notice this right away, use the example in the first section to compare this one with. That should make the difference apparent.
- “Now there isn’t a middle term, no x term in this polynomial. We can use the same steps when factoring, except that we need to make sure that when we add the factors, the answer ends up as 0. Let’s start by factoring the x2.”

Continued...