M&C3:  Boolean Expressions

Boolean expressions are essential to while loops and conditional statements. Students should know how to write Boolean expressions, how they are evaluated, and how Boolean expressions can be simplified.  Not fully understanding how Boolean expressions are evaluated in a while loop may lead to not understanding when the loop stops and what is executed in the loop.  Incorrect results or an infinite loop can follow.

When using Boolean expressions in while loops in Python, students may forget the difference between equality “==” and assignment “=”.  Python produces a syntax error when the assignment equality is used in a condition.