Slice it in Half!
Students will be able to draw lines of symmetry on 2-D shapes, classroom objects, and food items. Students will be able to identify if a shape or object has more than one line of symmetry.
Introduction (5 minutes)
- Explain to students that they will be learning about lines of symmetry today.
- Ask students if they know what the word symmetry means.
- Explain that a line of symmetry is the line they get when they divide something and both halves are exactly the same.
- Model a rectangle on the board, and invite a student to come to the board and draw the lines of symmetry.
Explicit Instruction/Teacher Modeling (10 minutes)
- Ask students to name objects around the class that when divided would have the exact same halves.
- List objects students come up with on the board.
- Ask students which objects would only have one line versus objects that would have more.
- When a student describes an object, have them come to the board to draw the object and the lines of symmetry on it.
- Ask students if lines of symmetry could be drawn on their faces.
Guided Practice/Interactive Modeling (30 minutes)
- Instruct students to get into groups of 4.
- List the following 2-D shapes on the board: triangle, square, rectangle, rhombus, kite, pentagon, hexagon, octagon, circle, oval, triangle, and trapezoid.
- Draw unfamiliar shapes on the board.
- Direct students to draw and cut the 2-D shapes out of construction paper.
- Ask students to work with partners within their group to draw the lines of symmetry on the shapes and fold the shapes to see if they are equal halves.
- Have students save the folded shapes in sandwich bags and put their group number with a permanent marker on the sandwich bag.
- Set the timer to 20 minutes.
- Discuss with students which shapes had lines of symmetry and how many. Discuss with students if any shapes had no lines of symmetry.
- Have each group talk about one shape and its lines of symmetry.
Independent Working Time (25 minutes)
- Instruct students to complete the Symmetry worksheet.
- Ask your students to complete the Your Half, My Half worksheet.
- Go over the worksheets as a class.
- Enrichment: Instruct students to complete the Learning Symmetry Owl worksheet. This worksheet is more challenging because there are more aspects to the image.
- Support: Ask your students to come to the back of the class. Guide them to draw food items they like on a sheet of paper. Ask if they would like to divide the item with a friend equally. Have them draw a line over the items to see if they can equally share or not. Explain that if they can cut the item into equal pieces, then the item has a line of symmetry. Instruct students to draw more lines of symmetry if possible, and ask if more equal pieces could be created out of that food item.
Assessment (20 minutes)
- Direct your students to complete Sailing the Sea worksheet.
Review and Closing (10 minutes)
- Have your students take out their sandwich bags from the lesson.
- Instruct a student to pull out a shape without looking and explain the lines of symmetry in that shape.
- Ask each group to do the same thing.
- Repeat this until all shapes have been covered.