Activity 

• Designate one color shape set for children and the other color shape set for you as the adult. Select at least 4 shapes (1 per child in the group) that match exactly from each shape set. 

• Give each child a different shape in one color (e.g., each child gets a blue shape).  

• Hold up a shape that exactly matches one of the children’s shapes from your own set (i.e., same shape and same size but in yellow).   

• Ask the children, “Who has the exact match for this shape?”   

• Ask, “How do you know the shape is a match?” The child might offer to fit their shape on top of your shape to “prove” the match.? 

• If children do not independently place their shape on top of yours, model doing so to support children in understanding if their shape is a match or not.  

• Ask children to name the shape; help as needed.  

• Repeat until all children have matched and named their shape.?  

• Repeat, giving children new shapes as time and interest allows.  

Adaptation Suggestions  

• Encourage children to trace both their shape and your shape to get a sense of how the shapes feel similar or different.  

Formative Assessment    

For children who need support

• Begin with using shapes that children are familiar with (e.g., equilateral triangle, circle). 

For children who need a challenge

• Hold up your shape in less familiar orientations (e.g., hold up a triangle with the point facing down, hold up a square so it looks like a “diamond,” etc.). 

• Use shapes that are less common, for example, rhombus or parallelogram.  

• After children have successfully matched the shapes, ask them to find objects in the classroom that are the same shape class (e.g., also a triangle).  

• • See a version of this activity at Shape Recognizer-Typical, and Shape Recognizer – Circles, Squares, & Triangles.

• We are not teaching the term congruence, but that is the mathematical term for “same shape and same size.” The “fitting” shapes on top of each other is an informal version of the mathematical justification of superposition. Big ideas for little kids! 
• Clements, D. H., & Sarama, J. (2021). Learning and teaching early math: The learning trajectories approach (3rd ed.). Routledge. https://doi.org/10.4324/9781003083528 

Activity 

• Designate one color shape set for children and the other color shape set for you as the adult. Select at least 4 shapes (1 per child in the group) that match exactly from each shape set. 

• Give each child a different shape in one color (e.g., each child gets a blue shape).  

• Hold up a shape that exactly matches one of the children’s shapes from your own set (i.e., same shape and same size but in yellow).   

• Ask the children, “Who has the exact match for this shape?”   

• Ask, “How do you know the shape is a match?” The child might offer to fit their shape on top of your shape to “prove” the match.? 

• If children do not independently place their shape on top of yours, model doing so to support children in understanding if their shape is a match or not.  

• Ask children to name the shape; help as needed.  

• Repeat until all children have matched and named their shape.?  

• Repeat, giving children new shapes as time and interest allows.  

Adaptation Suggestions  

• Encourage children to trace both their shape and your shape to get a sense of how the shapes feel similar or different.  

Formative Assessment    

For children who need support

• Begin with using shapes that children are familiar with (e.g., equilateral triangle, circle). 

For children who need a challenge

• Hold up your shape in less familiar orientations (e.g., hold up a triangle with the point facing down, hold up a square so it looks like a “diamond,” etc.). 

• Use shapes that are less common, for example, rhombus or parallelogram.  

• After children have successfully matched the shapes, ask them to find objects in the classroom that are the same shape class (e.g., also a triangle).  

• • See a version of this activity at Shape Recognizer-Typical, and Shape Recognizer – Circles, Squares, & Triangles.

• We are not teaching the term congruence, but that is the mathematical term for “same shape and same size.” The “fitting” shapes on top of each other is an informal version of the mathematical justification of superposition. Big ideas for little kids! 
• Clements, D. H., & Sarama, J. (2021). Learning and teaching early math: The learning trajectories approach (3rd ed.). Routledge. https://doi.org/10.4324/9781003083528