Distributive Property

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Objective

SWBAT use the distributive property to solve math problems.

Big Idea

This lesson will show students how easy mental math can be when using the distributive property

DO NOW

10 minutes

In this problem students will be solving the problem using any strategy that works for them.  I chose this problem because I will be using it again during the closure.  This problem fits nicely into using the distributive property.  In the beginning, I’m expecting to see students acting it out.(SMP 5)  This is ok, but by then end, I would like them to use the distributive property to show their work (SMP 7).

As students finish this problem, allow them time to share strategies with a tablemate (SMP3)

Using the Distributive Property to simplify math

15 minutes

During the power point, I’m going to start by showing the students how using the distributive property can make math easier.  I will break down some multi-digit multiplication problems for them.  Each time I do this, I’m going to stress that I didn’t need a calculator nor did I have to do “work” on my paper.  Every time I used the distributive property I could use mental math which makes solving multiplication problems easier.

Using the distributive property and the GCF

15 minutes

During this part of the power point, I’m going to be connecting back to the two strategies we used to find the GCF: list and the ladder.  The students will use the distributive property to make their addition easier.  Each time, students will be required to pull out the GCF.  According to the CCSS, the students will Use the distributive property to express a sum of two whole numbers 1–100 with a common factor as a multiple of a sum of two whole numbers with no common factor. For example, express 36 + 8 as 4 (9 + 2). 

I’m going to be using the phrase simplest form.  I will explain to the students that our goal is to get the numbers within the parenthesis to have no common factor except 1.  This thinking will help them when simplifying fractions.

For each example, I will be pointing out that we need to find the GCF.  They will do that on their own.  Once we find the GCF, I will be showing the students how to re-write the problem using the distributive property.

If they are using the list:  First, they will find the GCF.  Next they will find the factors that go along with the GCF.  The GCF will be on the outside of the parenthesis and the factors will be on the inside.  GCF(Factor + Factor)

If they are using the ladder:  First, they will find the GCF.  Next, they will find the factors by using the numbers on the top of the last step.  Again, the GCF goes outside of the parenthesis and the factors go inside.

Your turn

15 minutes

Students will practice re-writing addition problems using the distributive property.  I will be having the students using white boards so I can formally assess their understanding of this concept.  I will be looking at how students are finding the GCF and their understanding of the factors and where they go.  There are only 3 problems for them to do on their own which will be enough for me to see who still needs some help and who is getting it. 

I will be watching to make sure students pull out the GCF.  The first problem has only the GCF in common, but the other 2 problems have more than 1 factor in common.  According to the CCSS for 6.NS.B.4,  the remaining factors in the parenthesis can not having any factors in common except 1. 

Numbered Heads Together

20 minutes

I’ve created a power point with 8 questions. I’m going to use the NHT activity for two reasons.  One it allows students to use their tablemates as a resource if they get stuck and two, it allows me to walk around and target those students that had difficulty performing during the”your turn” part of the power point.  The problems I’ve chosen are examples from lesson plus some word problems.  It will be important that during the word problems to remind students to write the problem out mathematically to represent what is happening in the problem (SMP 2).  It may help to ask the students if they can write and solve using the distributive property.

 

Closure

10 minutes

I’m bringing back the problem that they solved during their warm up.  This time I’m going to be looking for students to use the distributive property to simplify this problem.  My directions will be to solve this problem in more than one way.  I will be looking for students to apply the distributive property to this problem.  Additionally, I will have the students explain in words what they did and why they did it to check for understanding of this concept.