If I were to show you a bowl containing apples and asked how many you see, you would probably have little trouble telling me the correct number.

How does that happen? Why does our brain recognize the number of apples in the bowl without the need to count them one by one?

This skill is called subitizing and it is the ability of looking at a group of objects and recognizing patterns that will allow us to “guess” the total number of objects without counting them one by one.

“Subitizing, coined in 1949 by E.L. Kaufman et al. refers to the rapid, accurate, and confident judgments of number performed for small numbers of items. The term is derived from the Latin adjective subitus (meaning “sudden”) and captures a feeling of immediately knowing how many items lie within the visual scene, when the number of items present falls within the subitizing range.”

source: Wikipedia


Let’s consider our bowl of apples:

How many apples are there?

By now you probably guessed that there are 5 apples in this bowl. The most interesting fact is that there is a high probability that we both perceived the total number of apples in different ways.

If you take a closer look at the pictures below, you will be able to see some of the possible ways to perceive the number 5 from the same bowl of apples:

Maybe you perceived 5 by adding 2, 2 and 1.  Maybe you perceived 5 by adding 3 and 2.  Maybe you perceived 5 by adding 4 and 1.  Maybe you perceived 5 by adding 2 and 3.

Isn’t this amazing?

Subitizing is a skill that greatly helps the development of number sense in early ages. The ability to recognize patterns in groups of objects helps students understand and build upon the concepts of one-to-one correspondence as well as conservation of number.

Subitizing should be introduced to young learners gradually. Teachers usually use dot plates or cards to “drill” their young students.  It is common practice to start with lower numbers and as the students get used to the possible patterns, the teachers introduce higher numbers that build upon the numbers already studied.

For example, by studying the following cards,

students will easily be able to figure out these.

Subitizing is an extremely important skill. What are your views on subitizing? How do you explore this skill in your classroom? Please share in the comments below.

Take care,