Should You Teach Subitizing?


Subitizing is an important ability that is critical to the development of efficient problem solving strategies and mental math skills. Providing activities and explorations to develop conceptual subitizing is emphasized over and over in the many math books and articles I read.


Our Flip Flop Math materials and activities provide students with explorations with both types of subitizing: perceptual subitizing (recognizing small groups of objects usually up to 5 without counting) and conceptual subitizing (combining small groups and seeing them as units).


Can you subitize these arrangements?

Make sure you ask students to explain how they know how many dots/objects they saw. You will hear a variety of strategies which will give you valuable information about your students' mathematical thinking. You will discover who needs to count all and who is able to see the groups as units and knows combinations of numbers. To read my blog, Can You Do This for Five Minutes Every Day?, click here.


I created a set of  84 subitizing cards with combinations up to five and ten (pair wise and five wise) using five and ten frames as well as regular and irregular dot patterns. I used research from Sousa, Van de Walle, and Wright. Click here for more information about the subitizing cards. You can purchase them at my Teachers Pay Teachers store.


Here is an example of a few of the subitizing cards representing doubles:


Doubles Dots #1aa


"Those children who cannot conceptually subitize are likely to have problems learning basic arithmetic processes. Can this innate ability of subitizing be strengthened through practice? The answer is yes."

-David A. Sousa (2008) How the Brain Learns Mathematics


"Children use counting and patterning abilities to develop conceptual subitizing. This more advanced ability to group and quantify sets quickly in turn supports their development of number sense and arithmetic abilities."

-Douglas Clements (1999) Subitizing: What Is It? Why Teach It?


 To read the article, Subitizing: What Is It? Why Teach It?, click here.


I just bought the book, Number Sense Routines, by Jessica F. Shumway (2011). She discusses many ways to incorporate numeracy routines every day in K-3 classrooms. Chapter 3, Visual Routines, provides ideas and activities for subitizing.