three-dimensional shapes - math grade 2 - lesson 48

1.TEACHER DO: Display all of the three-dimensional shapes that you have collected somewhere for students to see. Write the words FACES, EDGES, and VERTICES on the board.

TEACHER SAY: During our Reflect time yesterday, I showed this shape. Some of you mentioned that we can measure around the shape. Some of you mentioned that these shapes are challenging to measure because they are not flat.

TEACHER DO: Hold up the ball.

TEACHER SAY: Two-dimensional shapes are flat and have only two dimensions—length and width. These shapes have three dimensions, so we call them three-dimensional shapes. Repeat that with me.

STUDENTS DO: Repeat three-dimensional with the teacher.

TEACHER DO: Hold up a rectangular prism or cube and demonstrate how the shape has length, width, and height. Point to each dimension as you say them.

TEACHER SAY: These shapes have three dimensions—length, width, and height. We can measure how long they are, how wide they are, and how tall they are, or their height. You learned about some three-dimensional shapes last year in Primary 1. Just like two-dimensional shapes,these shapes have some special attributes and we need to learn some new vocabulary to describe them.Two-dimensional shapes have sides and vertices. Three-dimensional shapes also have vertices, but instead of sides they have edges and faces. I have written these words on the board. Let’s say them as I point to them.

STUDENTS DO: Repeat the words vertices, edges, and faces as the teacher points to them.

TEACHER SAY: Good. Now look at this shape I am holding and see if you might be able to tell what a face is, what an edge is, and where the vertices are.

TEACHER DO: If possible, allow students to handle and observe the shape.

TEACHER SAY: Turn to your Shoulder Partner and talk about the faces, edges, and vertices. Where do you think they are on this shape? Give a Thumbs Up when you have an idea to share.

STUDENTS DO: Talk to Shoulder Partner about the edges, faces, and vertices on the three-dimensional shape. Give a Thumbs Up when done. Selected students share their thinking about each vocabulary word and demonstrate using the three-dimensional shape.

TEACHER SAY: Good ideas. In most three-dimensional shapes, there are faces, edges, and vertices. Faces are the flat surfaces of a three-dimensional shape.

TEACHER DO: Point to the faces of the figure. Discuss the different shapes of the faces, if there are different shapes.

STUDENTS DO: Observe teacher Modeling where the faces are in a three-dimensional shape.

TEACHER SAY: Good. FACES are the flat surfaces of a three-dimensional shape. I will write that on the board.

TEACHER DO: Write definition on board after the word faces.

TEACHER SAY: An EDGE is where two faces meet.

TEACHER DO: Hold up the three-dimensional shape and run your finger along some edges. Demonstrate how an edge is formed when two faces meet.

STUDENTS DO: Observe teacher Modeling where the edges are in a three-dimensional shape.

TEACHER SAY: Let’s add that definition to our vocabulary.

TEACHER DO: Write the definition of the word edge on the board.

TEACHER SAY: VERTICES are similar to the vertices in a two-dimensional shape. They are the corners where edges meet.

TEACHER DO: Demonstrate how the edges of the shape come to a point, or corner, to make vertices. Write the definitions on the board under the word.

STUDENTS DO: Observe teacher Modeling where the vertices are in a three-dimensional shape.

TEACHER SAY: I have written the definitions of FACES, EDGES, and VERTICES on the board. Let’s look at more three-dimensional shapes and explore how many faces, edges, and vertices they have. Open your student book to page Lesson 48: Apply.

STUDENTS DO: Open student book to page Lesson 48: Apply.

TEACHER SAY: On this page, you will see a chart with the names and pictures of the three-dimensional shapes that I have. You may remember some of these, and some of them may be brand new. I will hold up a shape. Find it on the chart in your student book and put your finger on the name.

TEACHER DO: Hold up the cube and allow time for students to find it.

STUDENTS DO: Find the image of the cube and place their finger on the word “cube.”

TEACHER SAY: Great, you found it. This is a cube. We use dice a lot in math, but their shape name is cube. I am going to need a helper to count the faces.

TEACHER DO: Use Calling Sticks to select a helper.

STUDENTS DO: Selected student helps the teacher count the faces. All students record the number in the student book.

TEACHER DO: Use Calling Sticks to select additional students to help you count the edges and vertices.

STUDENTS DO: Selected students help the teacher identify and count the edges and vertices of the three-dimensional shapes. All students record the information in the student book.

TEACHER SAY: Great work. You are going to work in small groups to fill out the rest of the chart. I have collected multiple examples of each three-dimensional shape. Once you are in your group, one member will come up and select a three-dimensional shape. Work together to record the number of faces, edges, and vertices. Then return the shape and select a new one. Once you have been assigned to a group, take your student book and go sit with your group.

TEACHER DO: Help students Count Off to form small groups of 4 or 5.

STUDENTS DO: Move to work with their assigned group. Work together to identify and count the number of faces, edges, and vertices of all of the three-dimensional shapes.

TEACHER DO: Walk around the room to support students. Take note of students who may need additional instruction or support. When there are about 5 minutes of Learn time left, use an Attention Getting Signal to bring the group back.

TEACHER SAY: Wow. I heard lots of good thinking about faces and edges and vertices. Please return to your seats. Let’s go over the chart together. Make sure you correct any mistakes and fill in any blanks for shapes you did not get to.

STUDENTS DO: Return to seats.

TEACHER DO: Go over the answers for each shape. If time allows, have students help you demonstrate the answers. Otherwise, simply announce them.

STUDENTS DO: Selected students assist the teacher (if time allows). All students check answers, making corrections and filling in blanks as needed.

TEACHER SAY: I am so proud of you. You collected a lot of information about these three-dimensional shapes. We can use this chart to help us compare them and see how they are the same and different. Give your Shoulder Partner a high five and keep out your student book for Reflect.

STUDENTS DO: Give high five to Shoulder Partner.