Why is Subitizing so important?
-Teaghan Rooks

There are a number of advantages involved for students who develop skills in Subitizing; such as saving time, developing more complex number and counting skills, as well as improving their ability to deal with more complex number problems into the future (Reys, et al., 2012). Listed below are some of the most important reasons for developing Subitizing in students. 

• It saves time! 

 Subitizing numbers saves time through not having to count each individual member of group, but instead by simply perceiving the number immediately (Reys, et al., 2012). This comes in useful later on in Mathematics learning when students begin to deal with more complex numbers, or begin to deal with mathematical operations.

• It is an important precursor for more complex number ideas.

Early number order relations link directly to Subitizing skills, as students who can competently name small groups are able to understand number facts such as that 3>2 and that 4 is one less than 3. This complex understanding of numbers facilitates learning of other mathematical processes as they go on in their schooling. 

• It helps consolidate and develop more elaborate counting skills. 

Students who can Subitize small groups of numbers are able to develop their counting skills by beginning their counting after the subitized group, or by using subitizing to count forwards or backwards by twos, threes, or even larger groups later when they are exposed to more complex multiplication tables. (Reys, et al., 2012) This type of subitizing falls into the category of conceptual subitizing which occurs with larger number sets, and involves  breaking the group into smaller parts (Clements, 1999). 

• It quickens the process of learning addition and subtraction. 
  

When children are able to subitize, it means that they are better equipped to handle addition and subtraction concepts, as they do not have to count each small group to be added or removed when learning operations with manipulatives (Reys, et al., 2012). 

What are the big ideas of Subitizing? 

Perceptual vs conceptual Subitizing

Perceptual Subitizing
Closer to the basic definition of Subitizing, perceptual Subitizing involves identifying the number of a group, without counting or mathematical processes (Clements, 1999). Children are able to exhibit perceptual subitizing of numbers up to and including 4, without any previous knowledge of counting and without using mathematical processes (Charlesworth & Lind, 2013). As discussed in Clements, (1999) in some cases even infants can display elements of subitizing, by moving their eyes to the group of dots whose number corresponds to the number of beats heard by the child. This shows that although the infant has no previous mathematical skills or knowledge, is it possible for them to subitize small numbers.

Conceptual Subitizing
Conceptual Subitizing involves a different method, whereby the group is broken down into smaller parts of the whole, in order to be subitized more efficiently (Charlesworth & Lind, 2013). A student is able to conceptually subitize by searching for patterns within the group. Some of these patterns include larger spatial patterns such as those that can be found on dominoes, temporal and kinaesthetic, through use of finger patterns rhythm, and another is spatial-auditory (Clements, 1999). Conceptual Subitizing is also vital in the learning of arithmetic and subtraction, and those children who are not able to conceptually subitize may be at a disadvantage when they begin to learn these mathematical processes (Clements, 1999). 

Patterns in Subitizing

When looking in particular at spatial arrangements of groups, research suggests that certain arrangements easier to subitize than others, not just for young children but for students from primary through college (Clements, 1999). They tended to find that rectangular arrangements were the easiest for students to subitize, followed with linear, circular and then random or scrambled arrangements being the hardest to subitize. While all larger groups are naturally harder to subitize, the rectangular arrangements are able to be easily broken up into smaller easily distinguishable groups, for example six dots as arranged to the right, can be easily broken into two groups of three. 

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