Variables and Expressions

Overview

This 30-minute session is designed to introduce 6th grade students to the foundational concepts of variables and expressions in alignment with the Common Core State Standards (CCSS) for Mathematics, specifically:

• CCSS.MATH.CONTENT.6.EE.A.2: Write, read, and evaluate expressions in which letters stand for numbers.
• CCSS.MATH.CONTENT.6.EE.A.2.A: Write expressions that record operations with numbers and variables.
• CCSS.MATH.CONTENT.6.EE.A.2.B: Identify parts of an expression using mathematical terms, and interpret parts of an expression.

Students will grasp key vocabulary through explicit instruction, engage in collaborative Kagan activities, and demonstrate understanding through formative assessment.

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Learning Objectives ("I Can" Statements)

• I can define what a variable is and explain how it is used in mathematics.
• I can identify and write mathematical expressions using variables.
• I can distinguish between expressions and equations.
• I can create my own expressions using given variables.

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Success Criteria

Students will successfully be able to:

• Explain the meaning of variable, expression, and equation in their own words.
• Identify variables and constants in given expressions.
• Write expressions that include variables to represent simple situations.
• Collaborate with a classmate to develop original expressions.
• Answer comprehension checks using thumbs up/down gestures accurately.

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Materials Needed

• Whiteboard and markers
• Printed vocabulary cards (Variable, Expression, Equation) with dyslexia-friendly fonts (e.g., OpenDyslexic)
• Index cards with variables and numbers
• Student journals or notebooks
• Thumbs-up/thumbs-down cards for formative checks
• Timer or stopwatch for activity pacing

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Lesson Breakdown

1. Introduction – 5 minutes

• Explicit Vocabulary Instruction:
  Write and clearly define on the board:

  • Variable: A symbol (usually a letter) that represents a number that can change.
  • Expression: A math phrase combining numbers, variables, and operations (no equal sign).
  • Equation: A statement showing two expressions are equal (includes an equal sign).

• Use simple, age-appropriate examples:

  • Variable: x in 3x + 5
  • Expression: 3x + 5
  • Equation: 3x + 5 = 20

• Display dyslexia-friendly vocabulary cards and read aloud slowly to support all learners.

• Check for understanding with “thumbs up/down” after each definition.

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2. Guided Practice – 10 minutes

• Teacher Demonstration:
  Write several expressions on the board, highlighting variables and constants. For example:

  • 4 + y
  • 2a – 3
  • 5b + 7

• Discuss each example and ask students: “Is this an expression or equation?”

• Engage students with quick thumbs up/down responses after each prompt to affirm understanding.

• Model how to write expressions from simple word phrases, e.g., “a number plus 6” → n + 6.

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3. Kagan Cooperative Activity – 10 minutes

• Pair students (7 pairs + one trio for 15 students).
• Each pair receives index cards with variables (x, y, a, b) and number cards (1–10).
• Instructions: Together, create 3 different expressions using the variables and numbers provided. Encourage creativity! Examples might be: 2x + 5, a – 3, 7b + 2.
• Pairs write expressions in their notebooks.
• Each pair shares one expression aloud and explains the parts — teacher confirms correctness.

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4. Frequent Checks for Understanding – Throughout

• Use thumbs-up/thumbs-down signals during vocabulary instruction, guided practice, and after the Kagan activity.
• If multiple students show misunderstanding (thumbs down), briefly reteach or clarify.

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5. Closure and Formative Assessment – 5 minutes

• Individually, students write one sentence explaining what a variable is and write one expression using a variable.
• Collect journals to review and provide feedback.
• Remind students: Next lesson will dive deeper into evaluating expressions.

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Differentiation Strategies

• Support for Diverse Learners:

  • Use dyslexia-friendly fonts on all handouts and vocabulary cards.
  • Provide additional verbal explanations and visual examples.
  • Allow oral responses for students who struggle with writing.
  • Pair struggling students with supportive partners during the Kagan activity.

• Extension for Advanced Learners:

  • Challenge these students to create expressions including two variables, e.g., 3x + 2y – 5.
  • Ask them to explain in their own words how expressions can be parts of equations.
  • Provide simple real-world scenarios for them to model with expressions.

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Reflection for Teacher

• Observe pair interactions during the Kagan activity to assess social and mathematical learning skills.
• Use students’ journal entries and thumbs-up/thumbs-down responses to adjust pacing or reteach as needed in the next lesson.
• Consider using quick exit tickets next time to further review vocabulary retention.

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This lesson plan integrates hands-on partner activities, explicit vocabulary instruction using methods that support dyslexic students, and frequent formative checks within a tight 30-minute period—all fully aligned to the rigor and expectations of the Common Core State Standards.