# SUBITIZING, Part 3 – “The Why and The How”

In my last blog, I shared an experience I had while visiting with a friend and her two grandchildren, Maria and Omar, and what I noticed about their ability to subitize at four years of age.  As a Research Associate I am finding that the more I interact with young children, the more I am amazed at what they can do mathematically, specifically with subitizing. This is an area of focus for our Early Math Team.

For those who have been following my blog you might be asking, “So why should we spend time providing children with opportunities to subitize?”  From the research I have read, a child’s ability to subitize can serve to be very advantageous as children advance through their educational careers.

1. Subitizing saves time. Children no longer have to count each individual item in a group (collection or set).
2. It is an important precursor for more complex number ideas. Pattern recognition leads to the discovery of essential properties of number, such as the principle of conservation, allowing children to recognize quantity (the amount remains the same regardless of orientation). Additionally, children develop such capabilities as counting-on and composing/decomposing numbers (5 can be presented as 4 & 1, 2 & 3, or 2 & 2 & 1), both of which are valuable components of number sense (Clements 1999).
3. It helps consolidate and develop more elaborate counting skills. Children 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 forward or backwards by twos, threes, or even larger groups later.  For example, when a child is presented with a problem such as  “There are three cows in the field and each cow has four legs. How many legs in all?”  A child may respond 4 + 4 + 4 = 12 or 4 + 4  = 8 and 4 more is 12.

You might want to consider engaging your children in subitizing activities through games.  Below are some games that you might want to try at home or in your classroom.

For children ages 1 – 2:  Naming Quantities

Point out small collections in a child’s natural environment (up to 3).  For example: There are two shoes. I see two shoes. Two!

For children 3 – 5:  Which One is Not Like the Others?

Make three to four groups of items, for example you might make three piles of two and one pile of three and have child find the one that is not like the others.  Increase amounts based on what children can do.

For children 3 – 5:

Show students dot patterns (subitizing cards) and ask them to tell you what they saw. How did they see it?  (For some children you might want to let them recreate what they saw using chips, pennies…) Increase the number of dots based the student’s ability to subitize.

For all ages you might consider providing them with opportunities to play dice games, dominos, and matching (numerals to objects) – all of which support the development of subitizing.