Subitizing is the ability to quickly identify the number of items in a small set without counting. To do this effectively students are required to “see” collections or groups as opposed to counting one at a time. They need to see a configuration of objects and instantly know how many is there. This skill requires practice and support. The practice can come from things such as dot cards, ten frame cards etc. In these cases students can be shown the card quickly and then asked the question “How many did you see?” The support comes from the conversations that ensue. As students are asked to articulate their thinking about what they saw and how it supported them in knowing “how many” their thinking grows. As students hear from others how they “saw” the collection their thinking is supported.
The value of subitizing with your students is considerable. Research indicates that subitizing can play an important role in the development of mathematics skills including addition/subtraction, and multiplication/division. It can also support students development in number sense and can serve as an indicator for student success in mathematics.
Our curriculum has specific subitizing outcomes for Kindergarten and Grade 1 students. However, the value of this work can extend well beyond the primary grades. Subitizing activities can serve as a powerful warm up or Minds On activity to start a mathematics class at any level.
To support you with subitizing with your young mathematicians check out these Subitizing Cards.