Dice and dominoes are probably some of the first quantities we consciously subitize and assign a numerical value to as children. (Subitizing, you say? What’s that? Check out this post on the many nuances of counting.) The “pip” or dot patterns are consistent across dice and dominoes, which makes them easily subitized. Additionally, each dot pattern builds upon the previous which helps establish the idea of hierarchical inclusion.
Dice make an appearance in so many favorite childhood games: Trouble Pop-a-Matic, Yahtzee, Snakes and Ladders, Backgammon… and of course, some of our favorite classroom games like Tenzi and Shut the Box. Take a look at some of the math embedded in these dot patterns, particularly around number composition and relationships.
Dominoes introduce a whole new level of complexity while still tapping into subitizing. Rather than perceptual subitizing (the near-instantaneous recognition of a single quantity) dominoes develop conceptual subitizing: the ability to recognize two quantities at once and combine them into a total.
Playing with dominoes, or rolling two dice at once, supports a few different areas of math reasoning. Both present a child with two quantities simultaneously and allow for some interesting mathematical thinking. First, it moves children along the path from counting all to counting on. Counting all means counting from 1, so for that first 3/2 domino, or a roll of 3 and 2, a child would count “1, 2, 3…. 4, 5” dots. If a child subitizes the dots, she is more likely to see the 3 and count on “4, 5” to generate the total. This is a more efficient strategy. Most efficient, of course, is seeing two values (3 and 2) and combining them through additive reasoning, a skill that develops with experience and exposure… So get out those dice and domino games… Start with Tenzi or Shut the Box!