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Operators & Expressions

Ninth graders learn the operators that build expressions in code — arithmetic (+, %), comparison (==, >), and logical (and, or, not). Operators let programs calculate and make decisions. They match operators to meanings, then evaluate expressions.

Grade 9Operators & Expressions55 minutes1 class periodCSTA / ISTEExplicit teaching4 StandardsCSTA
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Lesson at a Glance

Everything you need before the bell rings

Learning Objectives

Students will be able to…

  • ✓Use arithmetic operators.
  • ✓Use comparison operators.
  • ✓Use logical operators.
  • ✓Evaluate expressions.
Essential Question

How do programs calculate and compare values?

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Lesson Phases
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Vocabulary Terms
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Standards Aligned
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Interactive Task
Match It · Interactive

Match the Operator

Project this and match each operator to what it does — tap the operator, then tap the meaning.

➕ Match each operator to what it doesTry it
Operator
What it does
Now tap the meaning!
The Lesson · Explicit teaching

55 minutes, five moves

Tap any phase to open the teacher moves and student actions.

1

Hook — More Than Math

6 min

How does code decide if you “win” or compute a score?

👩‍🏫 Teacher Moves

  • Pose the question.
  • Share ideas.
  • Set the goal.

🎒 Student Actions

  • Think.
  • Share.
  • Get ready.
2

Use — Operators

13 min

Students learn.

👩‍🏫 Teacher Moves

  • Send students to Match the Operator.
  • Match each one.
  • Note == compares, = assigns.

🎒 Student Actions

  • Match.
  • Say.
  • Note it.
3

Modify — Evaluate It

14 min

Students practice.

👩‍🏫 Teacher Moves

  • Evaluate 7 % 3.
  • Evaluate 5 > 2.
  • Evaluate True and False.

🎒 Student Actions

  • Modulo.
  • Compare.
  • Logic.
4

Create — Create

15 min

Students apply.

👩‍🏫 Teacher Moves

  • Write an expression.
  • Use a comparison in an if.
  • Combine with and/or.

🎒 Student Actions

  • Write.
  • Compare.
  • Combine.
5

Reflect — Reflect

7 min

Students close.

👩‍🏫 Teacher Moves

  • What does == do?
  • What does % do?
  • Complete the exit ticket.

🎒 Student Actions

  • Say it.
  • Say it.
  • Complete the exit ticket.
Standards Alignment

Built to the standards you report on

Aligned to the CSTA K-12 Computer Science Standards and the ISTE Standards for Students.

CSTA
3A-AP-14

Use operators and expressions in programs.

CSTA
3A-AP-16

Design and develop programs.

CSTA
3A-AP-21

Evaluate program correctness.

ISTE
5c

Reason about computation.

Differentiation

One lesson, every learner

Multilingual Learners

ELL / EMERGING READERS
  • Operator/meaning cards.
  • Frame: "== checks if ___."
  • Evaluate examples.

Support & Access

IEP / 504
  • Match + and ==.
  • Use 3 operators.
  • Use examples.

Stretch & Extend

GIFTED / EARLY FINISHERS
  • Use order of operations.
  • Combine logical operators.
  • Write a formula in code.
Materials

What to gather

  • 📽️Screen / board
  • ➕Operator cards
  • 💻Match the Operator
  • 📋Expression worksheet
  • 📓Notebooks
  • 🎫Exit-ticket slips
Vocabulary

Key terms — hover for a quick definition

operatora symbol that performs an actionexpressioncode that evaluates to a valuearithmetic+ - * / operatorscomparison==, >, < operatorslogicaland, or, notmodulo% — the remainderassignment= stores a valueevaluatecompute the result
Evaluate

Exit Ticket

Preview the three formative checks. Tap “Sample answer” to see what mastery looks like — hide them before you print for students.

QUESTION 1
What does == do?
Checks if two things are equal.
QUESTION 2
What does % (modulo) do?
Gives the remainder of a division.
QUESTION 3
What does "and" require?
Both sides must be true.

Reflect: operators & expressions.

Have students write and evaluate expressions. A printable expression worksheet is in the CS library.

Study · Flashcards

Study the key terms

Tap a card to flip it, then rate whether you knew it. Built from this lesson’s vocabulary.

🃏 Operators & ExpressionsFlip
Card 1
Term
Tap to flip →
Meaning
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Nice work!

Practice · Quiz

Check your understanding

A quick self-check with instant feedback, drawn from this lesson’s key terms.

📝 Operators & ExpressionsQuiz
Score: 0
1 / 6
Question 1
0%

Nice work!

Practice · Worksheet

Printable worksheet

A print-and-go review sheet with a built-in answer key. Tap “Show answer key” to reveal answers, or print the clean version for students.

🖨️ Operators & ExpressionsPrint
Name: ________________________
Date: ____________

Part A · Write the word that matches each meaning

Word bank: arithmetic, assignment, comparison, evaluate, expression, logical, modulo, operator
  1. ==, >, < operators
  2. a symbol that performs an action
  3. % — the remainder
  4. compute the result
  5. and, or, not
  6. + - * / operators
  7. code that evaluates to a value
  8. = stores a value

Part B · Show what you learned

  1. What does == do?
  2. What does % (modulo) do?
  3. What does "and" require?
Answer key — Part A: 1) comparison · 2) operator · 3) modulo · 4) evaluate · 5) logical · 6) arithmetic · 7) expression · 8) assignment
Part B: 1) Checks if two things are equal. 2) Gives the remainder of a division. 3) Both sides must be true.