Math.3.NBT.A.2

Common core State Standards

• Math:  Math
• 3:  Grade 3
• NBT:  Numbers & Operations in Base Ten
• A:  Use place value understanding and properties of operations to perform multi-digit arithmetic
• 2:
Fluently add and subtract within 1000 using strategies and algorithms based on place value, properties of operations, and/or the relationship between addition and subtraction.

Download Common Core State Standards (PDF 1.2 MB)

Talking About Math: Sharing Strategies
Lesson Objective: Share solutions and mathematical thinking
Grade 3 / Math / Student Voice
Math.3.NBT.A.2

#### Thought starters

1. How does Ms. Saul create an environment in which students are comfortable sharing their thinking?
2. What are the advantages of having students share different strategies for solving problems?
3. Why does Ms. Saul ask students about the importance of mental math?
10 Comments
I like the collaborative way the teacher illustrates addition and subtraction of numbers. Great.
Recommended (0)
Watching a short video was much clearer than reading about the procedure. I appreciate the teacher sharing her teaching .
Recommended (0)
Felecia Moore Love the worksheet and the cheers. Would use this activity as a small group or partner activity. Great way to informally assess students understanding and usage of different strategies.
Recommended (0)
Why does Mrs. Saul ask students about the importance of mental math in this video?
Recommended (0)
I was intrigued with how Mrs. Saul taught her children to explain their thinking. I was trying to see the blue sentence strips which I believe were aiding them in their explanations. Can someone tell me what they said? They were blocked from my view and too blurry for me to decipher. Thanks!
Recommended (1)

#### Transcripts

• Classroom Close Up: 3rd Grade Math: Carlos & Sara Present Their Solutions with Jennifer Saul

[01:00:30;10]
Narrator: Carlos and Sara are

Classroom Close Up: 3rd Grade Math: Carlos & Sara Present Their Solutions with Jennifer Saul

[01:00:30;10]
Narrator: Carlos and Sara are students in Jennifer Saul's third grade class. In this Classroom Close Up segment, we follow them during one math lesson.

Jennifer: "So, before we start our Mental Math, I'd like a review of why we do Mental Math. Why even bother? Sara?"

Sara: "We do Mental Math because there's math all over the world."

Jennifer: "Ah...Carlos?"

Carlos: "Like, when, when, like you're somewhere without pencil or paper, you have nothing to draw on, to check Mental Math, you can just do it in your brain. So, like, math is everywhere."

Jennifer: "Math is everwhere. You're right."

Carlos: We did Mental Math and in Mental Math we did splitting, jumps of ten, and decomposing.

Sara: My favorite is decomposing.

Jennifer: "Sara"

Sara: "I used decomposing. I broke 65 into 60 and 5. I broke 25 into 20 and 5. I added the 60 and the 20 and I got 80. I added the 5 to the 5, and I got 10. I connected the 10 to the 80 and I got 90."

Jennifer: "Show if you agree. Me too. Somebody solve it with another strategy, another Mental Math strategy. Carlos?"

Carlos: "I used splitting. I split 65 to 50 and 15. I added the 50 to the 25, equal. The 50 to the 25. That equal 75. I added the 75 to the 15. That equal 90."

Narrator: Later in the lesson, students are given a word problem and asked to solve it in three different ways, and share their solutions with the class.

Jennifer: "OK. Could I please have Carlos come up? Thank you so much. So, Carlos, explain to us what you did. Presentation voice."

Carlos: "I added all the two's first. 2-4-6-8. I put the eight down. I added. Then I added the ones. 1-2-3-4. Then I put four. Then I added the fours. 4-8-12-16. I put the six down. I carried the one. Then I put the one down, and it was 16 and... \$16.48."

Jennifer: "Do you understand his thinking? Great, Carlos. Let's give him a round of applause. Ready?"

Carlos: You don't supposed to be afraid of going up there, like, they're all your friends, still. Like, if, if you say something wroing, they, they don't do nothing. They just, like, correct it by thereself, but they don't say like "You're wrong." Then, but, you, like, you don't have to be, like, like nervous or nothing.

Sara: When you go up there, you know that

Jennifer: "Sara"

Sara: it's like we're a whole family. We're all friends.

Jennifer: "Can yo show how you did this? What did yo make first of all?"

Sara: "First I made a table. In the first two boxes, I put teachers and amount. For the first teacher, it's gonna cost \$4.12, then for the second teacher, I added 4 plus 4, \$4.12 plus \$4.12. Then, I got \$8.24. So, I put it there for the second teacher. For the third teacher, I added \$.840, 24 cents plus 8, \$4.12. Twelve dollars and thirty-six cents. For the fourth teacher, I added \$12.36 plus \$4.12 and then I got 6, \$16.48."

Jennifer: "We need to give Sara a roller coaster cheer. Ready?"

Sara: The cheer feels good 'cause you know that you did a great job.

#### Teachers

Jen Saul
English Language Arts Math Science Social Studies Arts / 3 / Teacher

### Newest

Teaching Practice

### Questions are More Important Than Answers

All Grades/ All Subjects/ Culture

Teaching Practice

### Empathy & Community

All Grades / All Subjects / Culture

TCH Special

### Student Centered Civic Discussion & Deliberation

Grades 6-12, All Subjects, Civic Engagement

TCH Special

### Structured Academic Controversy (SAC)

Grades 6-12, All Subjects, Civic Engagement

TCHERS' VOICE

Class Culture

TCHERS' VOICE

Lesson Planning

TCHERS' VOICE

Differentiation

TCHERS' VOICE

New Teachers