LEARN NC

K–12 teaching and learning · from the UNC School of Education

The variable machine

http://illuminations.nctm.org/LessonDetail.aspx?ID=L291

A lesson plan for Grades 3–5 Mathematics

Provider: National Council of Teachers of Mathematics

About this resource

Appropriate grades
3–5
Subjects
mathematics (algebra)
Provider
National Council of Teachers of Mathematics

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This lesson provides an introduction to the use of variables, and develops students' algebraic thinking. Students explore the idea of a variable as a symbol that can stand for any member of a set of numbers. The activity demonstrates how to substitute numbers for variables (letters) in order to discover unknown values.

Students learn to:

  • Represent the idea of a variable as an unknown quantity using a letter or a symbol.
  • Express mathematical relationships using equations.

North Carolina Curriculum Alignment

Mathematics (2004)

Grade 3

  • Goal 5: Algebra - The learner will recognize, determine, and represent patterns and simple mathematical relationships.
    • Objective 5.02: Extend and find missing terms of repeating and growing patterns.
    • Objective 5.03: Use symbols to represent unknown quantities in number sentences.
    • Objective 5.04: Find the value of the unknown in a number sentence.

Grade 4

  • Goal 5: Algebra - The learner will demonstrate an understanding of mathematical relationships.
    • Objective 5.02: Translate among symbolic, numeric, verbal, and pictorial representations of number relationships.

Grade 5

  • Goal 5: Algebra - The learner will demonstrate an understanding of patterns, relationships, and elementary algebraic representation.
    • Objective 5.02: Use algebraic expressions, patterns, and one-step equations and inequalities to solve problems.