##
* *Reflection: Connection to Prior Knowledge
Exploring Place Value Strategies While Journaling - Section 1: Warm Up

The students already know how to add and subtract, but knowing what I do now because of the Common Core, I have inserted many opportunities for students to solve work in their own way and journal about those solutions, before I introduce a new strategy or concept.

In doing this, I allow children to make their own sense before I scaffold them up. I have also found that I can teach "in the moment" and just add to their thinking, rather than asking them to think like me. Building on their prior knowledge, while they are applying that knowledge, makes learning seamless and important at the moment it is presented.

Expanded notation was just that today…important for the moment.

*Using Prior Knowledge to Introduce a New Concept*

*Connection to Prior Knowledge: Using Prior Knowledge to Introduce a New Concept*

# Exploring Place Value Strategies While Journaling

Lesson 3 of 10

## Objective: Students will be able to solve an addition problem and defend their thinking using a journal response.

#### Warm Up

*10 min*

As the students assemble, I place a 3 digit by 3 digit addition problem on the board and ask them to solve with a partner on their white boards. We have been working on strategies to efficiently and accurately solve problems, so I will watch for application of those strategies.

I introduce the term "expanded notation" to the students and ask them to tell me what they think "expanded" means. During this conversation, I listen for phrases and explanations that will help students remember what the term means.

Then I put 300 + 70 + 9 = 379 and ask the students to discuss why that makes sense and how they can use the word "expanded" to their discussion.

Now, I will tell the students that as they explore and solve problems today, they should try to use the strategy of expanding numbers into their values based on the place they are located.

*expand content*

#### Active Engagement

*25 min*

Students need many opportunities to explore and make sense of situations involving more than one step to solve a math problem. Today, my students are given the task of solving the problem 178 + 225 = n. I have asked them to use their understanding of expanding a number in some way to show their work.

This student wrote out both addends in their expanded form and then added the places together.

In this clip, you will see the student paired her current understanding of expanded notation to the model of base 10 blocks. She went on to circle the like blocks and then represented them in her solution.

*expand content*

#### Sharing and Closure

*10 min*

After allowing the students to share their different solutions at their tables, I remind them that learning to identify efficient strategies, like expanded notation, will help them mentally solve larger math problems.

I will also inform them that tomorrow we will be using only the expanded notation method to solve addition problems.

*expand content*

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- UNIT 4: Understanding Division
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- UNIT 6: Unit Fractions
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- LESSON 1: Mental Math with Place Value
- LESSON 2: Place Value and the Number Line
- LESSON 3: Exploring Place Value Strategies While Journaling
- LESSON 4: Adding 3 Digits to 3 Digits Using Expanded Form
- LESSON 5: Journaling About Place Value
- LESSON 6: Regrouping Using Riddles
- LESSON 7: Rounding to Check Accuracy
- LESSON 8: The Next Decade
- LESSON 9: Two Digit Subtraction With Rounding
- LESSON 10: Multiple Step Story Problems