1.OA.1

Standard

Use addition and subtraction within 20 to solve word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using objects, drawings, and equations with a symbol for the unknown number to represent the problem. (See Table 1)


Student Language:

    • "I can use different strategies for addition to solve word problems. (within 20)"
    • "I can use different strategies for subtraction to solve word problems. (within 20)"

Explanation

About the Math, Learning Targets, and Rigor

  • This standard builds on the work in Kindergarten by having students use a variety of mathematical representations (e.g., objects, drawings, and equations) during their work. The unknown symbols should include boxes or pictures, and not letters.
  • Use the addition symbol (+) to represent joining situations, the subtraction symbol (-) to represent separating situations, and the equal sign (=) to represent a relationship regarding quantity between one side of the equation and the other.
  • Contextual problems that are closely connected to students’ lives should be used to develop fluency with addition and subtraction.
  • Provide opportunities for students to participate in shared problem-solving activities to solve word problems. Collaborate in small groups to develop problem-solving strategies using a variety of models such as drawings, words, and equations with symbols for the unknown numbers to find the solutions. Additionally students need the opportunity to explain, write and reflect on their problem-solving strategies.

IMPORTANT: Key-word strategies in which children focus only on one or a few words will not work with algebraic problems. Teachers need to help all children move beyond such limiting strategies by emphasizing understanding & representing the situation.

Resources

Videos

  • Khan Academy
      • Scroll to 1.OA.1, click on skill, find videos on left side of each skill


Extra Practice