Unit 6 Geometry

Unit Driving Question

How does classifying geometric shapes and objects help us solve real-world problems?

Essential Questions

1. What do investigations tell us about the relationship among shapes?

2. In what ways are geometric figures similar and different?

3. What information can we gather from analyzing shapes?

4. How do we investigate measurable attributes of objects?

Big Ideas

1. An angle is determined by their measurement or size.
2. Tools and algorithms help define the perimeter and area of a 2-D shape.
3. Three-dimensional shapes are classified by their attributes.

Technology Resources

The following apps, websites, and smartboard lessons can be used throughout the unit, as needed, during small groups, lessons, to reinforce standards.  They are also useful for students who may need reinforcement, remediation, or differentiation.

• Third Grade List- This list has resources that can be used all year long.

Resources Within This Unit

• Big Idea 3:

• Seesaw Scavenger Hunt: If your school has iPads, your students can use the Seesaw app to take pictures of items around the school and ask each other questions. For example, a student may take a picture of a bookcase and ask what it’s shape is or how many angles it has.

Additional Resources

• Turtle Diary Geometry Games- This website includes multiple games to practice geometry concepts.

• Make Geometry Memorable by Scholastic- This is a list of interactive and online ideas that you can do in your classroom when teaching geometry.

• Area and Perimeter Explorer- A virtual manipulative you can use to teach students area and perimeter.

Launch Task

1 Lesson

Bedroom Investigation

A child’s room is a very special place, such a place with which every child can relate. The students will work on geometry and measurement simultaneously. This task focuses on the application of these two concepts.

Big Ideas for Development Lessons

3-4 Weeks

Big Idea 1: An angle is determined by their measurement or size.

Collaborative Engagement 

1. Shape Sort Challenge- Give students different shape manipulatives to look at. Have them describe the shapes in as many ways as they can. Challenge them to look at the sides and corners. As they describe the shapes in more simple terms (such as “the corners are small”), you can start defining terms (“smaller angles are called acute angles”). For teachers who do not have manipulatives, here are some shape cut outs.  Check out this link 

Key Resources 

1. Geometry Tasks: Third grade students will describe, analyze, and compare properties of two-dimensional shapes. They compare and classify shapes by their sides and angles, and connect these with definitions of shapes. Students also relate their fraction work to geometry by expressing the area of part of a shape as a unit fraction of the whole. Mathematically proficient students communicate precisely by engaging in discussion about their reasoning using appropriate mathematical language.
2. What's your Angle: Students find and model angles with the Angle Finder diagram.   
3. Guess My Shape: This is a great way to see what your students know. Students choose a polygon, draw it, and then cover it with a post it. They then describe the polygon using geometric clues and have a partner guess what it is. When their partner thinks they know what it is, they can check under the post- it. To make it more challenging, you could have students not be able to use the phrase “My shape looks like…” or have them only be able to make so many guesses. Other activities including 3 Card Shape Match and 2D Shape Compare can be found here. 

Big Idea Formative Assessment

1. 3rd Grade 2D Geometry Pretest and Posttest: This is an assessment that has a combination of 2-D shape questions. 
2. Angle Assessment: This assessment challenges students to define shapes based on their characteristics and angles.

Evidence of Understanding 

• Identify a polygon, such as a square, by its angles.

• Categorize the three types of angles based on their attributes. 

Big Idea 2: Tools and algorithms help define the perimeter and area of a shape.

Collaborative Engagement

1. Toothpicks and Tiles: Give students tiles and toothpicks in a bag. Give them a series of challenges to try to solve using a certain amount of tiles to toothpicks. The connection can later come that the “tiles” define the area and the “toothpicks” represent the area.

Key Resources 

1. Perimeter Tasks: This website includes both performance and assessment tasks for students to explore perimeter. The performance tasks are more hands-on, observation driven.  
2. City Farmers: This is a task that challenges students to find the area and perimeter of gardens based on the amount of space they need to grow certain flowers & vegetables. These real world problems give students the opportunity to think outside of the box.
3. Third Grade Area and Perimeter Unit: This is a large unit that includes many area and perimeter activities. Each task has a mini lesson that breaks down the task objectives. 

• Formative Assessments/Independent Practice 24 & 31
• Page 1-31- Understanding  Area & Perimeter
• Pages 32-41- Finding the Area using Measurement
• Page 41-90 More Complicated Area Tasks 

Big Idea Formative Assessment 

1. Area and Perimeter Assessments: These are a series of assessment questions that can be used as task cards or a quick check each day.
2. Third Grade Geometry and Measurement Questions: There are a combination of area questions and other review questions from prior third grade units. This could be used as a spiral review. 

Evidence of Understanding 

Determine the perimeter of a shape by counting the outer edges of the unit squares or adding the values of each side.

• Calculate the perimeter of a regular polygon by adding the lengths of each side.

• Find the value of the missing side based on the shape’s other measurements.

Identify the area of a regular polygon by placing unit squares within the shape.

Make connections between multiplicative representations and area models.

• Develop a formula, based on other mathematical concepts, that can be used to find the area.
• Use two digit by one digit multiplication strategies to help find the area of a shape. 

Big Idea 3: Three-dimensional shapes are classified by their attributes.

Collaborative Engagement 

1. Witch’s Hat: Challenge students to design a party hat for a witch. Their original design will be on paper (2-D), but then they can try to construct the hat with paper. Challenge them to come up with different designs other than rounded hats. Afterward, you can share designs and start “defining” the 3-D shapes of the hats.

Key Resources 

1. Geometric Solids: This tool allows you to teach about various geometric solids and their properties. You can manipulate and color each shape to explore the number of faces, edges, and vertices, and you can also use this tool to investigate the following question: For any polyhedron, what is the relationship between the number of faces, vertices, and edges? What other questions can this tool help you answer?
2. Solid Shapes: Identifying 3-D Shapes: Students will be able to identify geometric shapes in objects they use in their daily lives.
3. Seesaw Scavenger Hunt: If your school has iPads, your students can use the Seesaw app to take pictures of items around the school and ask each other questions. For example, a student may take a picture of a bookcase and ask what it’s shape is or how many angles it has.
4. I Spy: If technology is not available, you can start an I Spy game using geometry vocabulary. Example: I Spy a circular shape that is orange and black. Students can then name the 3-D shape and the object. 

Big Idea Formative Assessment

1. Designing Robots: Students can create robots. using recycled 3-D materials, such as tissue boxes, soda cans, etc.  They create their design and define the amount of 3-D shapes in each.

Evidence of Understanding

Identify and build 3-D shapes based on their attributes.

• The attributes, such as the number of vertices, edges, and faces, allow us to identify and construct the 3-D shape.

Pack and count the amount of squares within a 3-D shape.

• 3-D shapes have fillable space unlike 2-D shapes.
• The volume is the amount of squares that fit within a 3-D shape. 

Unit Closure

1 Week (includes time for probes, re-engagement, and assessment)  

• Bedroom Investigation Part 2 This is the revised version of the initial task that adds some rigor at the end of the unit.