Multiplying Radical Expressions

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SWBAT multiply radical expressions and simplify their answers completely

Big Idea

The skill building in this lesson allows students to demonstrate the distributive property and multiplying two binomials with radical expressions.

Warm Up

10 minutes

I plan for this Warm Up to take the students about 15 minutes to complete and for me to review.  This is longer than one of my typical Warm Ups, but I want to provide the students with several concepts and methods to multiplying radicals before they complete the Independent Practice.  I compare multiplying polynomials to multiplying radicals to refresh the students memory about the distributive property and how to multiply binomials.  

In the Warm Up, I provide students with several different types of problems, including:

  • multiplying two radical expressions
  • multiplying using distributive property with radicals
  • multiplying two binomials with radicals

I model reviewing the Warm Up in the video below.



Independent Practice

25 minutes

After reviewing the Warm Up, I work a few more examples for students before handing them the Independent Practice.  I want to make sure the students understand the structure of the problem, and the different ways to multiply. I show some of those examples below in the video. 

After I work the examples, students begin to work on the Independent Practice.  I walk around to monitor student progress and to assist students when needed.  Several students struggled with multiplying the binomials.  It seemed to help students when I take the first term, set it outside of the second parentheses to show distributive to multiply it to both terms. Then, repeat the same procedure for the second term in the first parentheses.

Exit slip

15 minutes

I hand the Exit slip to students about the last 15 minutes of class.  Again, like the Warm Up, I am allowing more time in this lesson for students to complete the Exit Slip.  In this Exit Slip, I instruct the students to find the area of the irregular shape.  Students have to sketch lines on the diagram to find regular shapes that they can use a formula to find the area.  Then they can find the sum of all the parts or areas.  

I use this Exit Slip as a quick formative assessment to check for student understanding of multiplying radical expressions.  

The reason I allow more time is that the third goal is for students to critique each others work in a nice manner.  The stronger students get at this skill, the better the class community.  Math Practice 3 helps students learn from correct answers, wrong answers, and conversations.