Suggested Grade Range: Kindergarten to Early Elementary (and beyond)
Subitising is the ability to recognize the number of objects in a group without having to count. It is an important early number concept that supports the development of “math thinking” and can be seen near the bottom of Fosnot’s Number Sense, Addition and Subtraction landscape.
A number of visuals and concrete materials can be used in the teaching and learning of subitising. One common tool is the dice.
Before a student can practice the skill of subitising using dice, the student first needs to have hands-on experiences using dice and recognizing the configuration of dice faces. Since dice are often used in games, by understanding the concept of the dice and being able to quickly recognize the number of dots on a dice face (or faces) students will be building social skills too!
Provide the student with 3-Dimensional tactile dice and give them an opportunity to explore. Discuss.
The student may identify:
Then, introduce additional types of dice, including large foam dice. Discuss.
The student will then find the circles on each 2-Dimensional tactile coloring page and fill in each dot. When they are finished, they will have one page completed for each dice face. Using a braille label, the corresponding number can be included to label the dice by its value.
One way to support the concept of dice and begin to make connections to 2-Dimensional dice is to collaboratively build an example of a dice from a net. The image will be run through the PIAF machine first so that the edges and dots are raised.
Using the Matching Dice Faces tactile graphics image, students will match dice faces. This will need to be cut after it has gone through the PIAF machine. When printing, ensure the dots on the dice faces are not significantly larger than a braille cell to ensure the student’s hands can move easily over the dots.
Since the goal of subitising is to build the recognition of the number of items (in this case dots) without counting, the student will be feeling the dots on the subitising cards for a brief period of time. Often, this skill is taught visually in the classroom through flashing an image quickly, then covering it up. The student will be given a stack of subitising flash cards using 2-Dimensional images of dice faces and an object to completely cover the cards. The dots on the subitising cards should be approximately the size of a braille cell to ensure the student’s hands can move easily over the dots. This can be done concurrently within the context of a larger class or one-on-one.
Download the attached Subitizing Images.
By Jamie Sellors