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.4

Understand subtraction as an unknown-addend problem. For example, subtract 10 – 8 by finding the number that makes 10 when added to 8.

• Cave Game Subtraction
The purpose of this task is for students to practice creating and memorizing subtraction equations, while focusing on missing addends.
The purpose of this task is to help students understand the commutative property of addition. Because the total number of dots is the same regardless of how a domino is oriented, the domino reinforces the idea that the addends can be written in any order.
• Fact Families
The purpose of this task is for students to identify and write sets of related addition and subtraction equations; these are often known as "fact families" because the equations are related by the same underlying relationship between the numbers. This task reinforces the commutative property of addition and using the relationship between addition and subtraction.
• Fact Families with Pictures
The purpose of this task is for students to reinforce students' understanding of "fact families." Fact families reinforce the commutative property of addition and using the relationship between addition and subtraction. Working with fact families is a common activity, although often times students are asked only to work with symbols. Also, the scaffolding for these tasks often only supports students in writing four of the eight possible facts in a family; this task purposefully scaffolds them to write all eight. In addition, this task includes a picture to anchor each fact-family; students can graduate from here to a symbols-only version of this task
• 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 Math Module 1: Sums and Differences to 10 (EngageNY)
In this first module of Grade 1, students make significant progress towards fluency with addition and subtraction of numbers to 10 as they are presented with opportunities intended to advance them from counting all to counting on which leads many students then to decomposing and composing addends and total amounts.
• 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.
• 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)

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 Specialist - Shannon Olson 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.