The word “subitizing” comes from Latin subito, meaning “quickly” and the act of subitizing is all about seeing a small quantity and knowing how many there are.
Subitizing is essential to building overall number sense and understanding more complex math concepts like addition and subtraction. This skill is “caught, not taught.”
Subitizing is all about seeing quantity, not counting it.
We cannot tell children how to subitize. We need to show them quantities and give them meaningful opportunities for their brains to do the work.
Subitizing is essential for building strong number sense. Watch this video below to try it out for yourself, and understand why it’s so crucial for young mathematicians.
Questions for Reflection:
What are some of your own misconceptions about subitizing?
What is one thing you can do, starting today, to shift your teaching practice when it comes to building number sense through subitizing?
Keep in mind that young children may not be able to explain their thinking or describe the arrangements they see right away (and that’s okay). It will take modeling, practice, and time.
Best Practices in Subitizing (“Do’s and Don’ts”)
DO use simple, high contrast colors, like black dots on a white field, to make the arrangement easier to see.
DON’T use more than one color in the beginning. You might strategically use different colors to emphasize a given operations strategy later on.
DO plan sequences of arrangements that gradually increase in difficulty.
DON’T make the sequence a regular or predictable pattern (ex/ increasing by one, skip counting, number of the day).
DO give your students a second look if they need more time to see.
DON’T show them an arrangement long enough for them to count and DON’T go back to confirm their answers by counting.
Young children should build the capacity to retain a mental image of the dot arrangement and rely on that instead of the image in front of them.
If you see students pointing or “tagging” dots, decrease the quantity and build up their perceptual subitizing skills with small numbers 1 through 4.
Use these dot arrangements as a starting point to create some dot sequences for your learners.
Remember that the more regular the arrangement (in a straight line, symmetrical, or similar to a known shape or pattern) the easier it will be for young brains to see that quantity.
See Literacy Connections (next in this section) for ideas to mathematize these concepts with children’s literature.