Reflection: Joy Who's a Widget? Making Sense of Definitions - Section 1: Launch: Who's a Widget? (How to Write Good Definitions)


To launch this task, I made a decision to give students a concrete example that would show the two components of good definitions: classification and differentiation.  By modeling this idea with an example for a strawberry--a red fruit that is juicy and has seeds on its surface--I was able to give my students a clear idea of what I was looking for.


When we shared out definitions to test by looking for counterexamples, I try to create safety for the presenting group by saying things like, “counterexamples are the best for revealing holes in our definitions” or “counterexamples help us to see opportunities to improve our definitions.”  Additionally, as students explained their counterexample, I tried to control the tone and energy in the room (students LOVE this activity!!!) by telling them that they aren’t trying to “win” or “show another group why they are wrong,” but instead, revealing a consideration the writing group would need to make for their definition.  

  Making Definitions Concrete
  Joy: Making Definitions Concrete
Loading resource...

Who's a Widget? Making Sense of Definitions

Unit 2: Introducing Geometry
Lesson 2 of 8

Objective: Students will be able to recognize and apply the components of a "good" definition (classification and differentiation). Students will be able to test definitions of terms by looking for counterexample.

Big Idea: Students will write precise definitions based on examples and non-examples and test these definitions by looking for counterexamples.

  Print Lesson
6 teachers like this lesson
Math, Geometry, deductive reasoning, definition, basic properties
  70 minutes
widget li resized
Similar Lessons
Reasoning About Rigid Motions
Geometry » Congruence and Rigid Motions
Big Idea: Students learn how to use reason as well as experience to understand the result of transforming a figure. Deductive and inductive logic work hand-in-hand!
Ault, CO
Environment: Rural
Tom Chandler
Proving It
Geometry » Line-sanity!
Big Idea: This lesson begins to builds students understanding of proofs using Algebra and Geometry.
Saratoga Springs, NY
Environment: Suburban
Stephanie Conklin
Parallel Lines Challenge Problem
8th Grade Math » Transformations
Big Idea: Challenge students to prove what they know about parallel lines and angle relationships when the diagram is unique and exact angle measures irrelevant.
Bowling Green, KY
Environment: Suburban
Christa  Lemily
Something went wrong. See details for more info
Nothing to upload