The teacher sorts three or four shapes into two categories according to a secret rule they have determined ahead of time (for example, triangles vs. rectangles). Then, the teacher asks children to guess their rule and figure out which category each additional shape should be sorted into. Once most children appear to have figured out the rule, the teacher asks the children to ThinkPairShare to describe it. The teacher then plays again with another rule.
Primary Objective
 Identifying shapes and describing the characteristics of shapes
 Sorting shapes based on different rules, such as shape family (for example, triangles vs. rectangles), geometric features (for example, shapes with four sides/angles vs. shapes with five sides/angles), and geometric properties (for example, shapes with four equal length sides vs. shapes without)
How to use
This activity can be adapted to make it easier or harder, depending on children’s current shape knowledge. If the activity seems too easy for children, try some of the Make It Harder challenges. If it’s too difficult, try some of the Make It Easier suggestions.
Materials
 Set of at least 15 shapes. You can use pattern blocks, tangrams, attribute blocks, and/or shapes you make from foam board or cardstock.
 Shape Sorting Mats (two sheets of paper of different colors)
 ThinkPairShare cards
 Silent icon card
Teacher Resources
 Sorting Rules: Ideas for sorting rules, organized by level of difficulty to adapt to children’s current shape knowledge
 Shape glossary: Sample language to use when describing shapes to children
 ThinkPairShare handout: Sample language to use when introducing the ThinkPairShare concept to children
Steps of the activity
The activity steps icons below outline the steps of the activity. Print these icons as cards and share them to help children remember the steps. They’re also a helpful scaffold for children!
Find a sample script for teachers to use here.
Setup 1
Teacher sorts four shapes based on the predetermined sorting rule.Setup 2
Teacher holds up the next shape and asks children to figure out where the shape belongs by guessing the sorting rule.Setup 3
Teacher verifies the correct answer and places the shape, continuing with more shapes until children can verbalize the rule.Instructions
Instructions for introducing the activity to the Whole Group .
Activity SetUp  
Choose which sorting rules and shape sets you are going to use. Review the Sorting Rules Handout for ideas. MAKE IT EASIER
MAKE IT HARDER


Activity WarmUp  
Today, we’re going to do an activity with shapes. First, we’re going to talk about the shapes we’re going to use. 
Using shapes from the shape set, show examples of shapes you will be using during the activity. Name the shapes that will be focused on during the activity. If you’re introducing new shapes to children, consider using the Shape Glossary Handout for definitions, language, tips, and examples. 
Introduce the Activity  
We’re going to play a shape guessing game! It’s called Guess My Rule. For some parts of this game, no one can talk—not even the teacher! Watch carefully as I sort shapes here (gesture to one side of the Shape Mat) or here (gesture to other side of the Shape Mat) and guess the rule I’m thinking about. Why am I putting some shapes here (gesture) and other shapes here (gesture)? 
Show children the shape set. 
Model the Activity  
Let’s give it a try! First, I’m going to put some shapes in two different groups following my secret rule. 
Put one shape at a time on either side of the Shape Sorting Mats, following the chosen rule (for example, triangles on one side and circles on the other). Place at least two shapes on each of the Sorting Mats (two sheets of paper of different colors). 
Now I need your help figuring out which side this shape (hold up another shape) should go on—but remember, your guess has to follow my secret rule! 
Hold up another shape without telling children which side it belongs on. 
Shhh … remember, no one talks during this part! If children need a reminder of what the Silent icon card means, explain: When I hold up this picture, we all have to be really quiet. Let’s practice! 
Show the Silent icon card to remind children to remain silent for this part. Encourage children to point as needed. MAKE IT EASIER
MAKE IT HARDER

On the count of three, everyone quietly point to the side you think this shape should go on. One, two, three… Place the shape on the correct side of the Shape Mat. 

Let’s try another shape (hold up another shape). 
Show another shape and continue the steps above (showing a shape, children pointing, placing the shape) until you have added at least three additional shapes (or until most children are consistently correct), with children quietly guessing where each belongs. 
Now, pause and ThinkPairShare with your partner and guess my rule. What was my rule for sorting these shapes? 
Remove the Silent icon card and encourage children to ThinkPairShare what they think the sorting rule is and why. Review ThinkPairShare as necessary. MAKE IT EASIER
MAKE IT HARDER

What was my rule? 
Ask children to share their guess for the rule after all have engaged in ThinkPairShare with a partner. 
You got it! My rule was… 
Confirm the sorting rule, reviewing why each shape met the rule or not as needed. 
Let’s try another rule! 
As time allows, play additional rounds using new sorting rules. 
Explore The Executive Function And Math Skills In This Activity
 DECIDE WHICH ONE PAGERS TO INCLUDE
 Executive Function Skills at a Glance: PreK Geometry and Spatial Activities
 ThinkPairShare: One Way to Practice Math and Executive Function
 [LINK TO TEACHER TOOLKIT WITH MATH+ EF ARTICLES]
What to do next
Do some children need more support or more challenge? Try the adaptation ideas to make the activity easier or harder. On another day, do this activity in Small Group.
This activity can be scaffolded to support all children’s shape knowledge. If the activity seems too easy for children, try some of the Make It Harder challenges. If it’s too difficult, try some of the Make It Easier suggestions.
Materials
 Shape set of at least 15 shapes. You can use pattern blocks, tangrams, attribute blocks, and/or shapes you make yourself from foam board or cardstock.
 Shape Sorting Mats (two sheets of paper of different colors)
 ThinkPairShare cards
 Silent icon card
Teacher Resources
 Guess My Rule Levels Handout: Ideas for different sorting rules, arranged by increasing difficulty
 Shape glossary Handout: Sample language to use when describing shapes to children
 ThinkPairShare Handout: Sample language to use when introducing the ThinkPairShare concept to children
Steps of the activity
The activity steps icons below outline the steps of the activity. Print these icons as cards and share them to help children remember the steps. They’re also a helpful scaffold for children!
Find a sample script for teachers to use here.
Setup 1
Teacher sorts four shapes based on the predetermined sorting rule.Setup 2
Teacher holds up the next shape and asks children to figure out where the shape belongs by guessing the sorting rule.Setup 3
Teacher verifies the correct answer and places the shape, continuing with more shapes until children can verbalize the rule.Instructions
Instructions for introducing the activity to the Small Group.
Activity SetUp  
Choose which sorting rules and shape sets you are going to use. Review the Guess My Rule Levels Handout for ideas. MAKE IT EASIER
MAKE IT HARDER


Activity WarmUp  
Today, we’re going to do an activity with shapes. First, we’re going to talk about the shapes we’re going to use. 
Using shapes from the shape set, show examples of shapes you will be using during the activity. Name the shapes that will be focused on during the activity. If you’re introducing new shapes to children, consider using the Shape Glossary Handout for definitions, language, tips, and examples. 
Introduce the Activity  
We’re going to play a shape guessing game! It’s called Guess My Rule. For some parts of this game, no one can talk—not even the teacher! Watch carefully as I sort shapes here (gesture to one side of the Shape Mat) or here (gesture to other side of the Shape Mat) and guess the rule I’m thinking about. Why am I putting some shapes here (gesture) and other shapes here (gesture)?

Show children the shape set shapes. 
Model the Activity  
Watch carefully as I sort shapes here or here following my secret rule. 
Put one shape at a time on either side of the Shape Sorting Mats, following the chosen rule (for example, triangles on one side and circles on the other). Place at least two shapes on each side of the Shape Sorting Mats. 
Now I need your help! Where does this shape go? 
Hold up another shape without telling children which side it belongs on. 
Time to Play!  
Help me figure out which side this shape (hold up another shape) should go on—but remember, your guess has to follow my secret rule! 
Continue holding up the shape between the two sides without telling children which side it belongs on. 
Shhh… remember, no one talks during this part! On the count of three, everyone quietly point to the side you think this shape should go on. One, two, three… 
Show the Silent icon card to remind children to remain silent for this part. Encourage children to point as needed. Place the shape on the correct side of the Shape Mat, regardless of children’s pointing. MAKE IT EASIER
MAKE IT HARDER

Let’s try another shape (hold up another shape). 
Show another shape and continue the steps above (showing a shape, children pointing, placing the shape) until you have added at least three additional shapes (or until most children are consistently correct), with children quietly guessing where each belongs. MAKE IT EASIER

Now, pause and ThinkPairShare with your partner and guess my rule. What was my rule for sorting these shapes? If needed, probe: 
Remove the Silent icon card and encourage children to ThinkPairShare what they think the sorting rule is and why. Review ThinkPairShare as necessary. MAKE IT EASIER
MAKE IT HARDER
Have children draw additional shapes fitting the rule (on whiteboard, paper, or on the floor with their finger) 
What was my rule? 
Ask children to share their guess for the rule after all children have engaged in ThinkPairShare with a partner. 
You got it! My rule was… 
Confirm the sorting rule, reviewing why each shape met the rule or not as needed. 
Let’s try another rule! 
As time allows, play additional rounds using new sorting rules. MAKE IT EASIER
MAKE IT HARDER

Explore The Executive Function And Math Skills In This Activity
 DECIDE WHICH ONE PAGERS TO INCLUDE
 Executive Function Skills at a Glance: PreK Geometry and Spatial Activities
 ThinkPairShare: One Way to Practice Math and Executive Function
 To learn more about math and executive function skills, click here for more resources! [LINK TO TEACHER TOOLKIT WITH MATH+ EF ARTICLES]
What to do next
Do some students need more support or more challenge? Try the adaptations provided for Small Group. Continue working in Small Groups with teacher support until students can comfortably play with minimal teacher guidance. Although there is no Centers version for Guess My Rule, some children enjoy the activity so much they may play it on their own during {{next_tab} time!