Connect everyday language with a formal truth table to introduce AND and OR to students.

  • Showing students how their spoken language connects to logic constructs can be incredibly helpful. 
  • Activity:
    • Step 1: Illustrate AND/OR using English
      • “I’m wearing a green shirt AND I am wearing blue shoes”” Point out that if you said AND, they both have to be true 
      • “I’m wearing a green shirt OR I am wearing blue shoes”IPoint out that since you said OR at least one one of these must be true.
      • When teaching logic, students will ask how to implement the English convention “and/or”, which is just OR. When students want to do “X and/or Y,” what they mean in logic is just X OR Y. 
    • Step 2: Replace English phrases with variables L and M
      • Note: Using variables A and B may be more common, but can create confusion in sentences because “A” is also a word. 
      • Introduce variables L and M to replace the phrases surrounding the logical operands with. Explain that it doesn’t really matter what the statement is!  Let’s call the first statement L and there other statement M. 
    • Step 3: Introduce logic tables
      • Walk through individual lines of the logic table and ask students to predict what the answer would be. Explain, if L is true and M is true, is L AND M true?  
      • After you’ve drawn out the table, introduce the mnemonic “OR means MORE” to help students remember that an OR creates more true statements.

More about this tip

External Source

Interview with Tammy Pirmann.

Interview with Pamela Fox