##### Unit Overview

In this unit, students build on their understanding of multiplication and division from Grade 3. They interpret a multiplication equation as a comparison, e.g., that the equation 35 = 5 × 7 is stating that 35 is 5 times as many as 7 and 7 times as many as 5. They will represent multiplicative comparisons as multiplication equations. The students will also multiply and divide to solve word problems involving multiplicative comparison e.g., by using drawings and equations with a symbol for the unknown number to represent the problem. They will distinguish multiplicative comparisons from additive comparisons. The students will solve multi-step word problems posed with whole numbers and having whole number answers using the four operations. These will include problems in which remainders must be interpreted to determine the solution. They will represent these problems using equations with a letter standing for the unknown quantity. And, finally, students will assess the reasonableness of answers using mental computation and estimation strategies including rounding.

**Essential Questions:**

- Why do I need mathematical operations?
- How do mathematical operations relate to each other?
- How is thinking algebraically different from thinking arithmetically?
- How do I use algebraic expressions to analyze or solve problems?
- How do the properties contribute to algebraic understanding?
- What is meant by equality?
- What do I know from the information shared in the problem? What do I need to find?
- How do I know which computational method (mental math, estimation, paper and pencil, and calculator) to use?
- How do you solve problems using addition, subtraction, multiplication, or division in real world situations?
- What are some strategies for solving unknowns in open sentences and equations?
- How do you estimate answers using rounding to the greatest place?
- How can you decide that your calculation is reasonable?
- What are different models of and models for addition, subtraction, multiplication, and division?
- What questions can be answered using the four operations?
- What are efficient methods for finding sums, differences, products, and quotients?
- How do addition and subtraction relate to each other?
- How do multiplication and division relate to each other?
- How do addition and multiplication relate to each other?
- How do subtraction and division relate to each other?
- How are parenthesis used in numeric expressions?
- What computation tools are best suited to which circumstances?

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

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.

CCSC Alignment: 4.OA.A.1, 4.OA.A.3

A.1: Multiplicative Comparisons through the use of Word Problems

A.3: Focus on solving word problems using arrays, equations, and multiplicative comparisons.

##### 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: 4.OA.A.3

To solve word problems where remainders must be interpreted with respect to context.