## Contents

Connections to the 3 Curriculum Threads

Featured Standards for Mathematical Practice

## Connections to the 3 Curriculum Threads

Learn more about the 3 Curriculum Threads

**Operations: **In this unit, students will come to understand that a number can be added and subtracted in different ways.

**Number: **Students will understand that numbers can be put together and taken apart in different ways.

**Equivalence: **Students will understand that there are different ways to make the same number.

## Content Standards Addressed

### K.OA.A: Understand addition as putting together and adding to, and understand subtraction as taking apart and taking from.

**K.OA.A.1: **Represent addition and subtraction with objects, fingers, mental images, drawings, sounds (e.g., claps), acting out situations, verbal explanations, expressions, or equations.

**K.OA.A.2: **Solve addition and subtraction word problems, and add and subtract within 10, e.g., by using objects or drawings to represent the problem.

**K.OA.A.3: **Decompose numbers less than or equal to 10 into pairs in more than one way, e.g., by using objects or drawings, and record each decomposition by a drawing or equation (e.g., 5 = 2 + 3 and 5 = 4 + 1).

## Featured Standards for Mathematical Practice

**S.MP.4. Model with mathematics.** Students will use multiple representations to model their mathematical thinking. Throughout the unit, they will have opportunities to use manipulatives, draw pictures, and act out situations.

**S.MP.5. Use appropriate tools strategically.** Students will use different tools to solve addition and subtraction problems within 10. They will have opportunities to choose different types of manipulatives. They may also choose to act out situations and draw pictures to represent their thinking.

**S.MP.6. Attend to precision.** As students explain their methods to solve problems, they will use precise language to communicate their ideas. Talk cards and sentence starters are valuable tools to help students use appropriate math language.

## Major Representations Used

Number tracks that represents the total used in the problem are used as a concrete visual of the total.

Two different colors of counters are used by students to represent the different addends that can be put together to make a total.

Two-sided counters are used to represent the different combinations of numbers.

Hoops or circles drawn on paper to help students as they physically move objects to different groups.

## Common Misconceptions

- Students may incorrectly count the number of cubes, either by skipping one or more cubes or by counting a cube more than once. Physically moving or touching the manipulatives used to solve the problems helps students develop one-to-one correspondence.
- Students may assume that the total number changes as different combinations are made. To focus students on the total and its parts, the number of manipulatives is limited and number tracks are used to provide a visual for the total.
- Students may have difficulty deciding if they should add or subtract to solve the problem. Using concrete materials and acting out the problem situations helps students recognize the action that takes place in the problem.