Assemble a collection of objects that includes real-world objects from your home or the classroom, classroom building blocks, and three-dimensional plastic shapes. Give each student a small ball of Play-Doh or modeling clay.
Say, “In a previous lesson we talked about two-dimensional shapes such as squares, circles, triangles, and trapezoids. Remember, two-dimensional shapes are flat. Today we are going to look at three-dimensional shapes. I have a collection of objects from my house and from our classroom. We are going to look at them very closely to see how they are the same and how they are different. Then we are going to compare them to the blocks in our classroom.”
Choose one of the objects that is a rectangular prism. Display it for the class to see. Pass it around for closer observation. “What can you tell me about this figure?” Allow students to respond, restating their observations using correct vocabulary, for example:
“Yes, the side with the picture is a rectangle. The flat side has four corners and four sides. Do you see other objects in the collection that have sides with the shape of rectangles?” Allow students to select similar boxes. “Good, we have more than one box that is like this one. The name for this shape is rectangular prism. Let’s say that together, ‘rectangular prism.’ How does the name help us remember the shape of these boxes?” Allow students to respond and guide them to notice that the word rectangular sounds like the word rectangle.
Show students a box that has been opened and lies flat, revealing the shapes of all sides. “Do you see how the rectangular prism is made of rectangles? How many rectangles are there?” (6) Count them together, using your finger or a marker to trace around each rectangular side. “Watch what happens when we put all of these rectangles together.” Fold the box back into its original three-dimensional shape.
“Do you see any other objects in our room that are rectangular prisms?” Allow a few students to respond, naming and/or pointing to objects in the classroom.
Repeat the above conversation using the example of a cube, a cylinder, a cone, a pyramid, and a sphere. Let students find similar shapes from the real-world objects, classroom building blocks, and three-dimensional plastic shapes. Use vocabulary terms to describe the surfaces as squares, circles, rectangles, and triangles. As you discuss each three-dimensional shape, ask students to create the shape out of Play-Doh or clay.
Present the names of each three-dimensional shape on large word cards and lay them on the floor, allowing room to place objects in groups around the cards. Starting with one shape, for example the rectangular prism, give individual students turns finding an object or a block to place in that group. “I have the word ‘rectangular prism’ on this card with a picture of what it looks like. Let’s look in our collection to find all of the objects that are also rectangular prisms and put them in a group together.”
Take a few minutes to be sure everyone agrees with the final groups and let students make any changes needed.
Remove the real-world boxes from the groups. “Let’s look at just the blocks from our classroom. Can someone find a cube?” Choose a student to find a cube from the collection while you flatten a piece of clay on a flat surface. “What shape will we see if I push one side of this cube into the clay?” Take a few guesses. “Let’s find out.” Press the flat side into the clay to create a square. “Were our guesses correct? How many square sides does this cube have? (6) Let’s learn more about all of these blocks using clay.”
Group students into pairs and make sure each pair has a ball of modeling clay and a collection of classroom blocks (one of each shape). Allow them to explore pressing blocks into the clay and describing the shapes they create. Walk around while they are working and use the vocabulary terms for the two-dimensional and three-dimensional shapes as you discuss what they are doing. “Which block has a flat side that is the shape of a circle? Yes, the cone. You’re right; there are two shapes with circles: cones and cylinders. What shapes do you get when you try the rectangular prism?” Collect the blocks and clay and briefly discuss student discoveries.
“What did you notice about the sphere, the cylinder, and the cone?” (They roll because the sides are not all flat, the sides are round; only one side makes a shape; etc.)
“What happened when you pressed these shapes into the clay?” (The sides that pressed in made other shapes.)
“How many corners does a triangle have?” (3)
“How many corners does a pyramid have?” (5)
“We have looked at a collection of objects from my house and from our classroom. You were able to put the objects into groups that are alike. Let’s review the names of the shapes we used.” Hold up an example of each three-dimensional shape and say its name. “You also looked closely at shape blocks and their sides. Let’s remember the shapes we discovered on the sides of these blocks.” Hold up an example of each block and name the two-dimensional shapes that describe the sides of each block.
“I’m going to show you another way to make a picture of the shapes on the sides of each block. Instead of using clay, we can also use paper and crayons to draw a picture.” Hang a piece of paper for all to see. Choose a shape and hold one of its flat sides up to the paper. “Watch how I can trace around the flat side of this block.” Trace the block and put it down. “What shape did I draw?”
“You have a choice at the workstations. You can draw shapes using blocks and boxes at workstations or you can use clay. Be sure you look at all the sides of each block or box and draw or stamp more than one if possible. For example, look at this pyramid. How many shapes could you draw or stamp using this block? Yes, two different shapes, a triangle and a square. At each station fill one sheet of paper with shapes that you trace using the objects, or stamp them into clay as we did in class earlier.”
Workstations should be set up so that each student has objects of similar shape (all rectangular prisms, all cubes, etc.). Include real-world objects, blocks, and three-dimensional plastic shapes at each station. Each station should have a supply of white paper and crayons or clay.
Assign students to workstations. Allow time for students to trace or stamp each object before rotating to the next station. Circulate around the room and reinforce vocabulary terms for the two-dimensional and three-dimensional shapes they are exploring.
Bring the whole class together to discuss their work at the stations. Hold up a student page and have students name the two-dimensional shapes as you point to them. Ask, “What object could have made these shapes?” and elicit the name of a three-dimensional shape. Repeat with a few other student papers.
Lead students in a discussion about how they could sort the blocks in the classroom using pictures they have traced. For example, shapes could be cut out and used as labels on the shelves to show where each type of block should be stacked.
This could be accomplished in many ways.
- Whole group: students could each be given a mixed set of blocks to sort and bring to the shelves after they are labeled.
- Small groups: each group could be in charge of one shape—finding all of the blocks and stacking them on the shelf.
- Workstation: sets of mixed blocks could be placed in grocery bags, and one bag could be sorted by each group as they rotate through the station.
Extension:
- Routine: Read-alouds would be appropriate for ongoing practice in identifying and naming two-dimensional and three-dimensional shapes. Books to consider may include:
- Shapes, Shapes, Shapes by Tana Hoban. Greenwillow Books, 1996.
- Shapes in Nature by J. Feldman. Children’s Press, 1991.
- Circus Shapes by Stuart J. Murphy, HarperCollins, 1997.
- Big Shapes for Little Kids by Susan Mascall and Bob Mascall. Fundangles, 1999.
- The Greedy Triangle by Marilyn Burns. Scholastic, 1995.
I Spy: Find a two- or three-dimensional shape in the classroom and give students clues about it. Students have to guess what shape you are thinking of. As students become more familiar with this game, ask them to give clues.
- Expansion: Provide boxes and/or blocks, paint, and large pieces of paper. Have students apply paint to one side of a box or block and print the shape on paper. Ink pads would also work if smaller three-dimensional shapes were provided. As students are working, ask them to name the shape they print and tell how many corners and sides it has. Ask them if this shape can be found on any other surface of the box.
Play Shape Bingo using two- and three-dimensional shapes.
Provide pairs of students with a Venn diagram copied onto an 11 x 17 (or larger) piece of paper. Tell students to pick two three-dimensional shapes. Instruct students to verbally compare and contrast the two shapes. Ask them, “How are the shapes the same? How are they different?” Capture students’ ideas on the Venn diagram.
- Small Group: Shape Detectives: Provide small groups with cards of various shapes. Direct them to be “Shape Detectives” by looking for items in the room that have the same shape as the shapes on the cards. As groups find each shape, have them yell “Shape Detective, (name of shape)!” When a group yells, the rest of the class must stop and wait for you to check the group to be sure they are correct.
Students who need opportunities for additional learning can practice with the vocabulary cards (M-K-4-2_Vocabulary Cards.doc).
