Alas, I had never heard this term. So I did some research and thought I’d share what I’d learned.

Subitizing is a way of instantly counting. In fancy math terms it would be getting to the cardinal number of a set (how many) without without going through the ordinals (counting each one’s position).

There are two types, perceptual and conceptual. Perceptual is perceiving the number of objects immediately. Conceptual is putting a little effort into it.

For instance, I glanced at the hot rollers Daughter had scattered on my side of the bed. I perceived there were three on the nightstand. But I had to do a little conceptual subitizing to arrive at the number of curlers on the floor (see the pictures).

[…] Bon Crowder encourages teachers to think deeply about preschool math in Counting Isn’t an Inherent Concept and What is Subitizing? […]