## Task Teacher Guide

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### In This Purposeful Practice…

Through this math talk and purposeful practice, students will engage with numbers within 10 and start to explore subtraction with teen numbers with the difference of 10 every time.

### Intentionality…

The purpose of the Day 2 activities is to reinforce key concepts from Day 1. Students will engage in a math talk and will have an opportunity to complete independent purposeful practice. The math talk and purposeful practice serve to develop a deeper understanding of the following big ideas.

- Understanding hierarchical inclusion allows for flexible composing and decomposing of numbers
- Numbers can be decomposed by separating a whole into two or more parts
- Subtraction names the missing part in terms of the whole
- Different subtraction situations will elicit different strategies
- Number relationships provide the foundation for strategies to help students remember basic facts
- Addition and subtraction are related in that addition names the parts in the whole and subtraction uses the whole to find a missing part.
- Subtraction can be used in either take away, comparison, or missing addend situations.
- Models can be used to connect concrete to abstract

## Math Talk

### Overview of this Math Talk

In today’s math talk, students will be exposed to a variety of questions that involve subtracting numbers within 10. The purpose of today’s math talk is to continue to provide opportunities for students to decompose numbers by separating the whole into two parts.

### Visual Math Talk Prompt #1

This math prompt has two parts: determining how many peaches are on the tree then determining how many peaches fell off the tree.

Show students the following visual math talk prompt and be prepared to pause the video where indicated:

Then ask students:

**How many peaches are on the tree?**

**How do you know?**

Encourage students to turn to their elbow partners or group members and have an open discussion about how many peaches were on the tree and how they could convince someone.

Discuss student strategies of how they knew there were 8 peaches on the tree.

Did they:

- Count each peach?
- Skip count by 2s?
- Subitize smaller amounts? (“I saw 3 peaches at the bottom, then 3 peaches at the side and 2 on the top. So I knew it was 8”)

After students share how many they counted and how they counted them (8 in total), continue playing the video for some of the peaches to fall to the ground.

Then ask students:

**How many peaches fell to the ground?**

**How do you know?**

Ask students to share how they determined the amount of peaches that had fallen?

Did they:

- Count back from 8?
- Count on from the 3 remaining peaches that were still on the tree?

Consider discussing the relationship between the subtraction and addition question.

**“How are they the same?”****“How are they different?”****“What is another way that the addition question could have been written?”**(3 + 5 =8) This is an example of the Commutative property. The order of addends in an addition question does not matter.

### Visual Math Talk Prompt #2

Show students the following visual math talk prompt and be prepared to pause the video where indicated:

Then ask students:

**How many peaches are on the tree?**

**How do you know?**

After students share how many they counted and how they counted them (10 in total), continue playing the video for some of the peaches to fall to the ground.

Then ask students:

**How many peaches fell to the ground?**

**How do you know?**

Again, take this opportunity to make the connection between the addition and subtraction number sentences displayed in the problem.

**“How does knowing the addition fact help us with the subtraction fact?”**

Addition and subtraction are opposite operations. The understanding of addition facts can help with subtraction facts as the numbers are the same but just in a different order. There is a relationship between 8, 2 and 10.

This may generate a discussion about “fact families”.

### Visual Math Talk Prompt #3

Show students the following visual math talk prompt and be prepared to pause the video where indicated:

Then ask students:

**How many peaches are on the tree?**

**How do you know?**

After students share how many they counted and how they counted them (9 in total), continue playing the video for some of the peaches to fall to the ground.

Then ask students:

**How many peaches fell to the ground?**

**How do you know?**

### Visual Math Talk Prompt #4

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### Visual Math Talk Prompt #5

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### Visual Math Talk Prompt #6

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## Purposeful Practice

### While Students Are Practicing…

### Game: Spinning Away From 10

### Small Group Assessment Opportunity

## Resources and Downloads

## Lesson Tip Sheet

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## Videos & Images

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## Keynote Slides

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## PowerPoint Slides

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## Printable Handout

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## Explore The Entire Unit of Study

This Make Math Moments Task was designed to spark curiosity for a multi-day unit of study with built in purposeful practice, and extensions to elicit and emerge mathematical models and strategies.

Click the links at the top of this task to head to the other related lessons created for this unit of study.

### Visual Number Talk Prompt #1

### Visual Number Talk Prompt #2

### Visual Number Talk Prompt #3

### Visual Number Talk Prompt #4

### Visual Number Talk Prompt #5

### Visual Number Talk Prompt #6

### Purposeful Practice Stations and Small Group Instruction