Editing Subitizing (section)

==Educational applications==
Historically, many systems have attempted to use subitizing to identify full or partial quantities. In the twentieth century, mathematics educators started to adopt some of these systems, as reviewed in the examples below, but often switched to more abstract color-coding to represent quantities up to ten.

In the 1990s, babies three weeks old were shown to differentiate between 1–3 objects, that is, to subitize.<ref name="Dehaene, S 1997"/> A more recent meta-study summarizing five different studies concluded that infants are born with an innate ability to differentiate quantities within a small range, which increases over time.<ref>{{Cite journal |author1=Rouselle, L. |author2=Noël, M.P. |name-list-style=amp |year=2008 |title=The development of automatic numerosity processes in preschoolers: Evidence for numerosity-perceptual interference |journal=Developmental Psychology |volume=44 |issue=2 |pages=544–560 |doi=10.1037/0012-1649.44.2.544 |pmid=18331143}}</ref> By the age of seven that ability increases to 4–7 objects. Some practitioners claim that with training, children are capable of subitizing 15+ objects correctly.{{Citation needed|date=December 2016}}

===Abacus===
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The hypothesized use of [[yupana]], an Inca counting system, placed up to five counters in connected trays for calculations.

In each place value, the Chinese [[abacus]] uses four or five beads to represent units, which are subitized, and one or two separate beads, which symbolize fives. This allows multi-digit operations such as carrying and borrowing to occur without subitizing beyond five.

European abacuses use ten beads in each register, but usually separate them into fives by color.

===Twentieth century teaching tools===
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The idea of instant recognition of quantities has been adopted by several pedagogical systems, such as [[Montessori]], [[Cuisenaire]] and [[Zoltan Paul Dienes|Dienes]]. However, these systems only partially use subitizing, attempting to make all quantities from 1 to 10 instantly recognizable. To achieve it, they code quantities by color and length of rods or bead strings representing them. Recognizing such visual or tactile representations and associating quantities with them involves different mental operations from subitizing.