Word of the day: subitize

The word-of-the-day from Anu Garg’s A.Word.A.Day is subitize (SOO-bi-tyz):

verb tr., intr.: To perceive, without counting, the number of objects in a small group.

From Latin subitus (sudden), from past participle of subire (to appear suddenly), from sub- (under) + ire (to go). Earliest documented use: 1949.

When you throw a die, you don’t count the number of pips to determine the value of the throw. You subitize. Now here’s a word you want to use when you take part in one of those “How many marbles are in the jar?” contests, though subitizing works only for a small group of items. Estimates of the upper limit of humans’ subitizing capability range from four to seven. Subitizing also depends on the arrangement of the objects.

Try this subitizing test.

Reading about this word (new to me) made me think of a sentence from Ralph Waldo Emerson’s essay “Thoureau” (1862):

From a box containing a bushel or more of loose pencils, he could take up with his hands fast enough just a dozen pencils at every grasp.

I suspect though that Thoreau was relying upon muscle memory, not subitizing. Oh well. Here’s a brief intro to Thoreau’s career in pencils.