Reflection: Developing a Conceptual Understanding To Change or Not to Change - Section 2: Exploration


Today I observed that the Algebra Tiles helped my students to better understand the meaning of the coefficient of a variable. One mistake that my students sometimes make when substituting a value into a variable term is to not multiply by the coefficient. If x=5, for example they sometimes say that 2x = 25. 

I found that asking them how many of each type of tile are represented in the expressions was helpful. After they built and wrote the simplified expression, I asked them:

  • How many x-squared's do you have?
  • Where do you see that in the tiles?
  • Where do you see that in the simplified expression?
  • Where do you see that in the original (unsimplified) expression?

These questions helped my students see that combining like terms was like counting and that the coefficient represents how many of each type of term exist or 'how many times' we counted it.

Several of my students were still confused about how to calculate exponents. Some were struggling with the different between x^2 and 2x, for example. Because of this I like to avoid choosing 1 and 2 as values to substitute for for variables at this stage of the unit.

  Combining as counting
  Developing a Conceptual Understanding: Combining as counting
Loading resource...

To Change or Not to Change

Unit 3: Equivalent Expressions
Lesson 7 of 23

Objective: SWBAT distinguish constant from variable terms and combine like terms using algebra tiles.

Big Idea: Students learn that constant terms do not depend on the value of variables.

  Print Lesson
Add this lesson to your favorites
Math, Expressions (Algebra), distributive property, like terms, algebra tile
  54 minutes
Similar Lessons
Determining Solutions
6th Grade Math » Equations
Big Idea: How can we prove equality? In this lesson students determine if a given number is a solution to an equation. Skill mastery is a focus.
New Haven, CT
Environment: Urban
Carla Seeger
Equivalent Numerical Expressions, Day 2 of 2
6th Grade Math » Intro to 6th Grade Math & Number Characteristics
Big Idea: How can you represent the area of a diagram using numerical expressions? Students connect their knowledge of area and equivalent expressions to the commutative and distributive properties for day 2 of this investigation.
Somerville, MA
Environment: Urban
Andrea Palmer
Distributive Property
6th Grade Math » Properties of Math
Big Idea: Students will compare the distributive property to sending invitations at a birthday party.
Brooklyn, NY
Environment: Urban
Ursula Lovings
Something went wrong. See details for more info
Nothing to upload