subitize

American  

[soo-bi-tahyz] / ˈsu bɪˌtaɪz /

especially British, subitise

verb (used with or without object)

Psychology.

subitized, subitizing

1. to make an immediate and accurate reckoning of (the number of items in a group or sample) without needing to pause and actually count them: for an average adult, the maximum number of such items is generally observed to be six.

   No one on our team was able to subitize the sets with eight or more triangles.

   It seems that some people can subitize more proficiently at certain times of the day.

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subitize British  

/ ˈsʌbɪˌtaɪz /

verb

1. psychol to perceive the number of (a group of items) at a glance and without counting

   the maximum number of items that can be subitized is about five

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Usage

What does subitize mean? To subitize is to identify the number of things in a set simply by quickly looking at them—not by counting them one by one.The practice of subitizing has its roots in psychology, but it is now taught in some preschools and early grades in addition to traditional counting.Example: Humans can subitize up to seven objects at once without having to count.

Etymology

Origin of subitize

First recorded in 1945–50; from Latin subit(us) “sudden” or Late Latin subit(āre) “to appear suddenly” ( subito ) + -ize

Example Sentences

Below five, we’re able to subitize, or rapidly judge numbers of items without counting.

From New York Times