# Gr. 1 Unit: Represent & Solve Problems Involving Addition & Subtraction

**LESSON UNIT**

**LESSON PLANS**

**LESSON SEEDS**

### UNIT OVERVIEW

In this unit, students apply and extend their understanding of addition and subtraction from their work in Kindergarten. They extend their understanding of addition as putting together and adding to and subtraction as taking apart, taking from, and comparing. In Kindergarten, students solved word problems within 10 using objects or drawings. They learned to decompose and compose numbers up to 10. Now students in Grade 1 will 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. They will use objects, drawings, and equations with a symbol for the unknown number to represent the problem. They will also solve word problems that require the addition of three whole numbers whose sum is less than or equal to 20. They should use objects, drawings, and equations with a symbol for the unknown number to represent the problem.

**Essential Questions:**

- Why do I need mathematical operations?
- How do mathematical operations relate to each other?
- How do I know which mathematical operation (+, -) to use?
- How do I decide which representation to use when solving problems (concrete manipulatives, pictures, words, or equations)?
- How do I know which computational method (mental math, estimation, paper and pencil, and calculator) to use?
- What is meant by equality in mathematics?
- How do I know where to begin when solving a problem?
- How does explaining my process help me to understand a problem’s solution better?
- How do I decide which strategy will work best in a given problem situation?
- What do I do when I get stuck?
- How do I know when a result is reasonable?
- What is the relationship between solving problems and computation?
- Why is the ability to solve problems the heart of mathematics?
- What are efficient methods for finding sums and differences?
- What questions can be answered using addition and/or subtraction?

A question is essential when it stimulates multi-layered inquiry, provokes deep thought and lively discussion, requires students to consider alternatives and justify their reasoning, encourges re-thinking of big ideas, makes meaningful connections with prior learning, and provides students with opportunities to apply problem-solving skills to authentic situations.

**UNIT LESSON:**

Represent and Solve Problems Involving Addition & Subtraction

Additional information such as Teachers Notes, Enduring Understandings,Content Emphasis by Cluster, Focus Standards, Possible Student Outcomes, Essential Skills and Knowledge Statements and Clarifications, and Interdisciplinary Connections can be found in this Lesson Unit.

**AVAILABLE MODEL LESSON PLANS**

The lesson plan(s) have been written with specific standards in mind. Each model lesson plan is only a MODEL - one way the lesson could be developed. We have NOT included any references to the timing associated with delivering this model. Each teacher will need to make decisions related ot the timing of the lesson plan based on the learning needs of students in the class. The model lesson plans are designed to generate evidence of student understanding.

This chart indicates one or more lesson plans which have been developed for this unit. Lesson plans are being written and posted on the Curriculum Management System as they are completed. Please check back periodically for additional postings.

Use Addition & Subtraction within 20 to Solve Word Problems

CCSC Alignment: 1.OA.A.1

Four activities that provide the opportunity for students to solve various types of addition and subtraction problems.

**AVAILABLE MODEL LESSON SEEDS**

The lesson seed(s) have been written with specific standards in mind. These suggested activity/activities are not intended to be prescriptive, exhaustive, or sequential; they simply demonstrate how specific content can be used to help students learn the skills described in the standards. Seeds are designed to give teachers ideas for developing their own activities in order to generate evidence of student understanding.

This chart indicates one or more lesson seeds which have been developed for this unit. Lesson seeds are being written and posted on the Curriculum Management System as they are completed. Please check back periodically for additional postings.

CCSC Alignnment: 1.OA.A.1-2

Students use double ten frames and counters to make combinations up to 20.

Counters on a Double Ten Frame

CCSC Alignnment: 1.OA.A.1

Students use 'think addition' to solve a missing number subtraction problem.

CCSC Alignnment: 1.OA.A.1-2

Enrichment Lesson Seed with two activities.

Solve Addition Word Problems with Three Addends

CCSC Alignnment: 1.OA.A.2

Students solve problems and visit centers that revolve around solving addition word problems with three addends.