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Mathematics - Elementary Curriculum Mathematics Grade 1
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Strand: OPERATIONS AND ALGEBRAIC THINKING (1.OA)

Represent and solve problems involving addition and subtraction within 20 (Standards 1-2, 5-6). Understand and apply properties of operations and the relationship between addition and subtraction (Standards 3-4). Work with addition and subtraction equations (Standards 7-8).

Standard 1.OA.8

Determine the unknown whole number in an addition or subtraction equation relating three whole numbers. For example, determine the unknown number that makes the equation true in each of the equations 8 + ? = 11, 5 = ? - 3, 6 + 6 = ?

  • Equality Number Sentences
    The purpose of this instructional task is for students to help students understand the meaning of the equal sign and to use it appropriately.
  • Find the Missing Number
    This task asks students to solve addition and subtraction equations with different structures so that they are able to see the connections between addition and subtraction more easily.
  • Georgia Standards of Excellence Mathematics
    GeorgiaStandards.Org (GSO) is a free, public website providing information and resources necessary to help meet the educational needs of students. The goal of this web site is to provide information that will enhance and support teaching and learning of Georgia standards.
  • Grade 1 Unit 3: Operations and Algebraic Thinking (Georgia Standards)
    In this unit, students will explore, understand, and apply the commutative and associative properties as strategies for solving addition problems. Share, discuss, and compare strategies as a class. Connect counting on to solving subtraction problems. For the problem 15 7 = ? they think about the number they have to count on from 7 to get to 15. Work with sums and differences less than or equal to 20 using the numbers 0 to 20. Identify and then apply a pattern or structure in mathematics. For example, pose a string of addition and subtraction problems involving the same three numbers chosen from the numbers 0 to 20, such as 4 + 13 = 17 and 13 + 4 = 17. Analyze number patterns and create conjectures or guesses.
  • Kiri's Mathematics Match Game - 1st Grade
    In this activity students play a game in small groups that requires them to find sums or differences.
  • Operations and Algebraic Thinking (1.OA) - First Grade Core Guide
    The Utah State Board of Education (USBE) and educators around the state of Utah developed these guides for First Grade Mathematics - Operations and Algebraic Thinking (1.OA)
  • Using lengths to represent equality
    In this task students work in pairs and use Cuisenaire rods or paper strips cut to whole centimeter lengths. One student puts a few rods (or strips) end-to-end. The other student matches that length with a different combination of rods (or strips). When two different ways of making the same length are found, the students write a number sentence reflecting the equality.
  • Valid Equalities?
    The purpose of this task is to help broaden and deepen students understanding of the equals sign and equality. In this task, students must attend to the meaning of the equal sign by determining whether or not the left-hand expression and the right hand expression are equal. This task helps students attend to precision.


UEN logo http://www.uen.org - in partnership with Utah State Board of Education (USBE) and Utah System of Higher Education (USHE).  Send questions or comments to USBE Specialists - Patricia  Stephens-French or Molly  Basham and see the Mathematics - Elementary website. For general questions about Utah's Core Standards contact the Director - Jennifer  Throndsen.

These materials have been produced by and for the teachers of the State of Utah. Copies of these materials may be freely reproduced for teacher and classroom use. When distributing these materials, credit should be given to Utah State Board of Education. These materials may not be published, in whole or part, or in any other format, without the written permission of the Utah State Board of Education, 250 East 500 South, PO Box 144200, Salt Lake City, Utah 84114-4200.