# Missing Puzzle Pieces

## Curriculum Goal

#### Primary: Geometry and Spatial Sense

• Sort and identify two-dimensional shapes by comparing number of sides, side lengths, angles, and number of lines of symmetry.

## Context

• The teacher shows a series of images at the front of the class. Students must clearly communicate which piece(s) completes the puzzle.
• This lesson can also be easily adapted to an online environment.
• Teachers may choose to share the slides with their students or not.
• Google Slides file has prompts in the notes section for teachers. Educators may wish to delete these before sharing with students.

## Lesson

• Present students with a puzzle problem from the Appendix.
• See individual slides for specific instructions.
• Ask students to think about how they would communicate which piece(s) complete the puzzle.
• If possible, have the students take turns sharing how they know the solution of the puzzle to classmate.
• As the challenges become increasingly difficult, facilitate discussion around the solution.
• Elicit reasoning as to why some pieces could not be possible solutions.
• Move on to the next problem when you feel the students are ready.
• This challenge does not need to be completed in one day.
• This challenge is intended to be revisited, allowing students to strengthen their mathematical spatial language over time.

## Look Fors

• Are children using gestures to visualize the shapes in different orientations?
• Are children using accurate directional language when discussing the puzzle?

## Related Lessons

A possible introductory lesson for students learning the names of shapes.

Students use spatial language to learn about the properties and orientations of shapes.