Tennessee Curriculum Center

Eliminating Possibilities

How often have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth?
Sherlock Holmes / Sir Arthur Conan Doyle
Overview

About this teacher move

Eliminating Possibilities is a problem-solving strategy through which possible answers are removed until only the correct answer remains. When everything is first open to consideration, clear thinking about eliminating options that are ineffective, irrelevant, flawed, weak, or wrong narrows the choices until only the best alternative remains. This practice is often used during test-taking, especially with multiple choice and matching items.

Implementing this teacher move

Have students keep charts or tables to structure their thinking and to record factors that were eliminated and in what order.

Managing this teacher move with students

 

  1. Introduce a problem that can be solved using logical thinking and eliminating possibilities.
  2. Steps in Eliminating Possibilities...

 

Understand the Problem

 

  • Identifying the key pieces of information needed to find the answer.
  • Students may have to read the problem several times and state the problem in their own words.

 

Choose a Strategy

 

  • Eliminating possibilities is particularly useful when there are several possible solutions and a set of criteria that the solution must address.
  • Creating a chart would assist in eliminating possibilities that do not meet the established criteria.

 

Solve the Problem

 

  • List the facts of the problem.
  • Work through each criteria to find the eliminate options that are not possible solutions.

 

Check

 

  • Read the problem again to be sure that the problem was solved or the question answered.
  • Determine if this is the best solution for this problem or if there are other satisfactory ways to solve the problem.

 

Explain

 

  • Because this strategy involves logic, it is important for students to explain or write about their thinking.
  • Demonstrate how to write a paragraph describing the steps taken and how decisions were reached.

 

Guided Practice

 

  • Have students try solving another problem using the eliminating possibilities strategy.

 

References