Lesson 4: Logical Operators

We have learned a lot of new terms so far! Let's review some of these terms through a game of CS Bingo.

Distribute: Give each student a unique CS Bingo Card.

Do This: Review the instructions for playing CS Bingo.

Do This: Play the music clip to cue the CS Bingo activity. Choose a random definition and read it aloud to the class. Give students a moment to check their bingo card for the correct term, then state the correct term. Repeat until a student yells "Java."

To allow for multiple students to "win" the game, continue pulling definitions until a couple more students win as well.

We previously learned to use the NOT operator to negate a Boolean expression. We have also learned to use nested if statements to check multiple conditions before executing a block of code. There are more logical operators that we can use to check multiple conditions in one line.

Do This: Review the lesson objectives.

Group: Place students in pairs.

Do This: Direct students to Level 1 on Code Studio to investigate the program with a partner. Students make the changes to the program as prompted.

Do This: Click through the animated slide to introduce the logical operators.

Do This: Click through the animated slide to define and demonstrate compound Boolean expressions.

Discuss: Click through the animated slide to display the prompts. Use the Retrieve-Pair-Share strategy to discuss the prompts.

• How might logical operators help us simplify the use of conditional statements?
• In the previous lesson, we used nested if statements to solve this scenario. How would this solution change using logical operators?

Discussion Goal: Students suggest using logical operators instead of multiple or nested if statements to check whether multiple conditions are true or if at least one of two conditions are true. Students share examples of how they would rewrite the code they wrote in the previous lesson to use logical operators instead of nested if statements.

Do This: Explain the example conditional statement using a logical operator.

Compound Boolean expressions can get pretty complex and sometimes are tricky to evaluate. We can use a tool called a truth table to help us evaluate compound Boolean expressions.

Do This: Define truth table.

Even though compound Boolean expressions can get complex, every compound Boolean expression can be broken down into our three core logical operators: not, and, and or.

Do This: Click through the animated slide to demonstrate the truth table for A || !B.

Do This: Define short-circuited evaluation.

Do This: Direct students to complete the Truth Tables handout.

You have learned a lot about how software engineers use conditionals and logical operators in their programs! Let's take a moment to reflect on your progress in developing your software engineering skills.

Do This: Have students respond to the reflection prompts on the Unit 4 Guide.

Do This: Review the concepts covered in this lesson.

Display: Key Vocabulary

Check For Understanding Question(s) and solutions can be found in each lesson on Code Studio. These questions can be used for an exit ticket.

To assign questions from the AP Classroom Question Bank that align with this lesson, create a custom quiz in AP Classroom by searching the Question Bank for the Essential Knowledge statements listed at the top of this lesson plan. You can find instructions and video demonstrations to do this on AP Central.

The following Topic Questions in AP Classroom can be assigned as a formative assessment for this lesson:

• Topic Questions 3.5

Note: Some Learning Objectives and Essential Knowledge statements in the suggested Topic Questions are covered in later units.