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

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http://illuminations.nctm.org/LessonDetail.aspx?ID=L29

A lesson plan for grades K–2 Mathematics

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Students investigate subtraction more directly, beginning with the easier “take away” mode. They model “take away” subtraction with buttons and write subtraction sentences. Illuminations provides helpful handouts and detailed instructions for completing the lesson.

Students will:

  • Determine the results of removing sets.
  • Review the term “difference”.
  • Investigate subtracting zero and subtracting all.
  • Find a missing addend.

NCTM Standards and Expectations:

  • Develop understanding of the relative position and magnitude of whole numbers and of ordinal and cardinal numbers and their connections.
  • Count with understanding and recognize “how many” in sets of objects.
  • Understand the effects of adding and subtracting whole numbers.
  • Develop and use strategies for whole-number computations, with a focus on addition and subtraction.
  • Use a variety of methods and tools to compute, including objects, mental computation, estimation, paper and pencil, and calculators.
  • Use multiple models to develop initial understandings of place value and the base-ten number system.
  • Develop a sense of whole numbers and represent and use them in flexible ways, including relating, composing, and decomposing numbers.
  • Understand various meanings of addition and subtraction of whole numbers and the relationship between the two operations.
  • Develop fluency with basic number combinations for addition and subtraction.

North Carolina Curriculum Alignment

Mathematics (2004)

Grade 1

  • Goal 1: Number and Operations - The learner will read, write, and model whole numbers through 99 and compute with whole numbers.
    • Objective 1.01: Develop number sense for whole numbers through 99.
      • Connect the model, number word, and number using a variety of representations.
      • Use efficient strategies to count the number of objects in a set.
      • Read and write numbers.
      • Compare and order sets and numbers.
      • Build understanding of place value (ones, tens).
      • Estimate quantities fewer than or equal to 100.
      • Recognize equivalence in sets and numbers 1-99.
    • Objective 1.03: Develop fluency with single-digit addition and corresponding differences using strategies such as modeling, composing and decomposing quantities, using doubles, and making tens.
    • Objective 1.04: Create, model, and solve problems that use addition, subtraction, and fair shares (between two or three).

Grade 2

  • Goal 1: Number and Operations - The learner will read, write, model, and compute with whole numbers through 999.
    • Objective 1.01: Develop number sense for whole numbers through 999.
      • Connect model, number word, and number using a variety of representations.
      • Read and write numbers.
      • Compare and order.
      • Rename.
      • Estimate.
      • Use a variety of models to build understanding of place value (ones, tens, hundreds).
    • Objective 1.03: Create, model, and solve problems that involve addition, subtraction, equal grouping, and division into halves, thirds, and fourths (record in fraction form).
    • Objective 1.05: Create and solve problems using strategies such as modeling, composing and decomposing quantities, using doubles, and making tens and hundreds.

Kindergarten

  • Goal 1: Number and Operations - The learner will recognize, model, and write whole numbers through 30.
    • Objective 1.01: Develop number sense for whole numbers through 30.
      • Connect model, number word (orally), and number, using a variety of representations.
      • Count objects in a set.
      • Read and write numerals.
      • Compare and order sets and numbers.
      • Use ordinals (1st-10th).
      • Estimate quantities fewer than or equal to 10.
      • Recognize equivalence in sets and numbers 1-10.