By Christina Mulcahy, Julia Ratchford, Crystal Day-Hess, and Douglas H. Clements
Don’t Burn Your Feet will get your child jumping around—inside or out—while exploring shape concepts. You can download the instructions and ideas for making this activity easier or harder here or at the end of this article. Here’s a summary of how to play:
Set up the game by making different shapes on the ground or the floor. The easiest way to make shapes is to use sidewalk chalk to draw on a driveway or sidewalk. If the weather is bad or you prefer to play inside, you can make the shapes by using masking, washi, or painter’s tape. You could also cut out or draw shapes on sheets of paper and put them on the floor.
To play the game, explain to your child that the ground is “hot lava” (they can imagine a volcano has just erupted!) and they have to jump on the shapes you tell them so that they don’t “burn” their feet.
Then, tell them different rules for what shape they should jump on. For example, for children just learning the names of shapes: Jump on the triangles—so you don’t burn your feet! For children ready for more of a challenge: Jump on shapes with three sides—so you don’t burn your feet!
Many people wouldn’t consider geometry an important math topic for young children. However, learning about shapes sets the foundation for geometry skills. Shape knowledge not only lays the groundwork for geometry concepts that students will learn and build upon in elementary school and beyond, but it can also improve children’s number and arithmetic learning. 
Older toddlers start by being able to recognize common examples of circles, squares, and triangles. But young children’s shape knowledge can go beyond these familiar shapes. As their skills grow, they can recognize less-common examples of these shapes. They soon learn to identify sides and then corners or angles of shapes.
Once children can identify sides and angles, these skills support their ability to recognize less-familiar shapes, like hexagons, trapezoids, and rhombuses. As they did with familiar shapes, children will first recognize common examples of these shapes. Later, they will be able to recognize more challenging examples. Finally, children will be able to think about shapes in terms of their attributes, such as right angles or parallel lines. 
You can support your child’s developing shape knowledge by adapting Don’t Burn Your Feet to make it more or less challenging. These adaptation ideas progress from early to advanced geometry skills. For more adaptations and shape examples, download the handout here or at the end of this article.
In addition to helping your child develop early math skills, math games like Don’t Burn Your Feet can also promote critical thinking and language skills. Playing with a variety of rules and asking your child questions about their thinking can help build their language, logic, and problem-solving skills. Here are some ideas to get you started:
Shift between rules using different shape parts and numbers. For example, go from “shape with three sides” to “shape with four angles.”
After your child jumps on the correct shape, ask them how they knew it was the right shape. If necessary, follow up with more than one question:
Try using these special cases:
We are curious to know how you used this activity. What adaptations worked for your family? What did your child like about the game? We also welcome any questions you may have. Please send your stories and questions to firstname.lastname@example.org.
The authors are members of the DREME Network and part of the Math+ project. Christina Mulcahy is a postdoctoral fellow at the Marsico Institute of Early Learning and Literacy at the University of Denver. Julia Ratchford is a Counseling Psychology doctoral student and graduate research assistant at the University of Denver. Crystal Day-Hess is a Research Assistant Professor and Assistant Director of the Marsico Institute for Early Learning at the University of Denver. Douglas Clements is the Kennedy Endowed Chair in Early Childhood Learning and professor at the University of Denver, and the executive director of the Marsico Institute of Early Learning and Literacy at the Morgridge College of Education.
 Clements, D.H., & Sarama, J. (2011). Early childhood teacher education: The case of geometry. Journal of Mathematics Teacher Education, 14, 133-148.
 For a full explanation of children’s development of geometry and shape knowledge, see LearningTrajectories.org.