Spatial Reasoning Focus:
- Visual-spatial working memory
- Visual chunking strategies
- Spatial language
- This is a teacher led activity, which can be conducted with a whole class or small groups.
- Students should have previous knowledge of symmetry and line of symmetry.
- Computer and projector
- Download: Square Tile Grid Symmetry Quick Image PPT
- Assortment of plastic square tiles (red, yellow, blue, and green) for each student
- 10 x 10 grid (1″ increment) for each student with a line of symmetry drawn down the middle
In this quick image activity, students will be presented with a series of reflection challenges made of square tiles and vertical/horizontal line of symmetry. Students will be asked to visualize the images and to create the mirror half of the image from memory.
- Present students with half of a symmetrical design (figure 1) for five seconds.
- Invite students to create the mirror half of the image from memory, ensuring that each piece they place is symmetric to a piece in the original image. Some students may choose to create the original as well as the reflected image, whereas others might choose to create the reflected image only. Depending on the complexity of the shape, and the needs of the students, the image can be shown again to allow students to notice additional features while they build.
- After sufficient time for building, show the original image again, and have students compare it with their own.
- Facilitate discussion and sharing about student’s strategies for how they approached the task.
- Repeat the process with other half-designs.
- For challenges with horizontal line of symmetry, ask students to rotate the grid to match the image.
Questions to Extend Student Thinking
- How can you tell/prove that what you have created is symmetric to the image shown on the board?
- Did counting the empty squares help you?
- How many square tiles in all (both sides of symmetry) were needed for this picture?
- Did you find it easy, medium or difficult to build the mirror half from memory?
- What made the challenge easy/medium/difficult?