Subtract Your Way

Grade 3: Unit 3: Lesson 7

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Let’s subtract numbers within 1,000!

Number Talk: Subtract Two- Digit Numbers

Warm-Up

Find the value of each expression mentally.

1. 50 - 10

b. 58 - 10

c. 258 - 20

c. 258 - 24

Let’s Talk About It!

• How was place value helpful as you subtracted these numbers?

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Strategies to Subtract

Activity 1

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• MLR 7: Compare and Contrast
• Representation

Find the value of each difference in any way that makes sense to you. Explain or show your reasoning.

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1. 428 - 213

b. 505 - 398

c. 394 - 127

Let’s Talk About It!

• Create a visual display that shows how you found the value of ______. You may want to include details such as notes, diagrams, drawings, and so on, to help others understand you thinking.

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• 5–7 minutes: gallery walk

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• What is the same and what is different about the ways that groups represented the subtraction?

Base Ten Drawings

Activity 2

• MLR 8: Discussion Supports

Jada and Han made drawings to show how they used base-ten blocks to find the value of 262 - 135 Their drawings are shown.

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How are their drawings alike? How are they different?

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Here are three expressions, followed by three diagrams. Write each expression next to the diagram that represents it. Then, find the value of the expression.

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252- 181

262- 135

252- 132

Let’s Talk About It!

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• What did you have to pay attention to as you matched each diagram to an expression?

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Lesson Synthesis

• Today we subtracted numbers using many different strategies. What is your favorite representation to use to subtract numbers?
• Does the way you subtract numbers or the representation you use change based on the numbers in the problem?
• Keep all these strategies in mind as we learn new ways to show our reasoning around subtraction in the upcoming lessons.

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Subtract within 1,000

Cool-Down

Find the value of 372 - 158. Explain or show your reasoning.

Cool-Down: Subtract Within 1,000

Image Citations

https://giphy.com/stickers/transparent-smartick-5v46dtzijjDO33RvHc

https://giphy.com/gifs/thelonelyisland-snl-saturday-macgruber-iKBAAfYNDu1dowhnEj

https://giphy.com/gifs/HBOMax-selena-gomez-and-chef-s2-y9XCVEKx02Q3tyHSD5

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