Factoring (Day 1 of 3)

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SWBAT factor expressions by identifying the greatest common monomial factor.

Big Idea

Students will use their knowledge of multiplication and factors to simplify expressions.


10 minutes

Students will complete the Do-Now in five minutes. While students are working I will pass back graded exit cards from our last class, and ask them to examine any mistakes that were made.

Students volunteers will then come up to the board to write down their answers. Then, a student will read the objective, "SWBAT factor expressions by identifying the greatest common monomial factor."

I will ask students to share out their prior knowledge about what a greatest common factor (GCF) is in math, and to give a few examples. I will then ask students to make a prediction about the definition of a greatest common monomial factor.

Guided Notes + Practice

30 minutes

Students will follow along with this Presentation using these Guided Notes. I expect them to take notes as we proceed. 

The easiest way for me to begin describing how to find the Greatest Common Monomial Factor (GCMF) to my students is through a non-algebraic example. Then, I will show my students that we are simplifying expressions using division. I will guide students to a formal understanding of the definition of GCMF on Slide 6 of Factoring Day One by illustrating the many possible monomial factors, but stressing that the GCMF is "8" since it has the greatest value.

For the majority of my students, the division method in Slide 6 is sufficient and they are able to move forward in the lesson. I stress to students to verify each response by using the distributive property, and to ensure that it matches to their original expression.

The biggest issue that I have with my students make when learning this skill is that they will correctly divide out a monomial that is a common factor, but not the GCMF. To combat this, I will ask students to list as many common factors as possible, and then to select which one is the greatest. Even though this method can be tedious in the beginning, students get a better understanding of the skill at hand, and are usually able to mentally find the GCMF after completing a few examples.

Students that are still having trouble with this concept have more success by writing out expressions in expanded form as seen on Slide 8. I will give students the option to use either method as they continue to work in pairs on the Practice section of their notes.

Clicker Questions

30 minutes

Students will work in pairs to answer the Clicker Questions. My students will respond using Promethean clickers, but this activity can be adapted using whiteboards or by having students hold up the number of fingers to correspond to a given answer.

To get the class excited, I will frame the clicker questions as a game of "Teacher vs. Students". If 80% of the class gets a question correct then they will receive one point; if the percentage correct is less than 80% I will receive the point. I will encourage students to work together, and to verify responses with the distributive property. My classes always get very excited during "Teachers vs Students", and I normally incorporate a small prize for the side that has the most points at the end.


10 minutes

I will ask a few volunteers to summarize what we learned today. I will then ask a student to come up to the front of the room to show a common mistake that an absent student might make when learning this skill, and a way to combat this error. I try to choose a student whom I observed helping his/her partner during the Clicker Questions activity. My goal is to showcase a model of how to offer help to a peer as we work through the challenging content that lies ahead.

Students will then complete an Exit Card on their own. This brief assessment will help me to plan for tomorrow's lesson.