Subitize this!

In very young children, right-brain dominancy gives the ability to “subitize” large quantities. Wikipedia defines subitizing as a “rapid, accurate and confident judgment of number.” This is something we can all do up to a small number of items – usually around 4 or 5. The maximum number of items most adults can subitize is around 10 to 12 (although it will typically take longer to do so, and the person will feel less confident doing it). After that, you’re either guessing or counting.

When a very young child looks at a large number of items, she doesn’t need to guess or count to see how many are there. The child can instantly see 48 marbles, in just the same way that the rest of us can instantly see 4 – by subitizing. The only thing the child doesn’t know, however, is how to tell us what she sees. She doesn’t know that this number is called “forty-eight.” In other words, the labels for quantities are what we need to teach the child.