Student Actions

Teacher Actions

• Develop conceptual understanding of numbers by being actively engaged in a variety of activities, such as part-part-whole, dominoes, and creating tally charts, that help them make connections to find patterns in groups of objects to quickly identify smaller qualities that can be mentally added together to get the larger value in a variety of settings. 

• Develop strategies for problem-solving by using manipulatives, such as fingers, dice, dominoes, cards, double ten frames, Rekenrek frames, and snap cubes, to recognize patterns in small groupings that can help students subitize numbers up to 20.

• Develop the ability to communicate mathematically by participating in whole group and small group number talks and games using grade-level appropriate vocabulary to communicate and have appropriate peer interactions using agreed-upon rules. 

• Develop the ability to model, generalize, and draw conclusions while they subitize. Students will explain how and which strategies they used to recognize various patterns of groupings to be able to know the quantity without counting.

• Pose purposeful questions to students as the teacher circulates among groups. Ask questions such as “How did you know that makes ________?”  How did you see that number?”  “Tell your neighbor how you saw that.” “Did they see it the same way or can they find another way?”

• Model and demonstrate strategies of how to subitize using a variety of tools such as dot cards, dominoes, and dice by briefly showing the objects and having the students tell the number displayed. 

• Support productive struggle while questioning students about how they see given numbers illustrated or modeled. 

• Incorporate appropriate vocabulary while leading conversations about subitizing. The ability to subitize can be developed and uses a student’s pattern recognition skills. Part-part-whole understanding is used to subitize numbers over four or five. This means a student looking at this pattern doesn’t usually see 7, but instead 1 and 6, or maybe 2 and 5.  

• Build procedural fluency in subitizing by scaffolding from perceptual subitizing (subitizing from very small sets) to conceptual subitizing (larger groups), using various manipulatives to increase the number of sets as students identify patterns of the smaller sets that can be grouped together to form larger sets.

Key Understandings

Misconceptions 

• Perceptual Subitizing (subitizing from very small sets) must come before Conceptual subitizing, which involves larger groups because students will need to use perceptual subitizing in order to break up the larger groups into parts.

• Ten-frames and other counting graphic organizers can be used to help guide students into recognizing smaller groupings within a larger set of objects.

• It is important to physically construct and deconstruct groups in a set to connect meaning while developing number sense. 

• Not know the number names and/or guess.

• Not realize that a number names a quantity.

• Subitizing involves counting

• Only the answer is important, it does not matter about patterns and/or groupings 

  Knowledge Connections

Prior Knowledge

Leads to 

• Subitize quantities of objects in arrangements up to 10. (K.N.1.4)

• Count using one-to-one correspondence. (PK.N.2.2)

• Use subitizing and grouping to demonstrate fluency of addition and subtraction facts up to 20. (2.N.2.2)