ABSTRACT
The purposeful selection of materials and activity design can enhance the mathematical language used by students. To be able to effectively operate on numbers, students need a strong number sense. A key element of number sense is subitizing. Subitizing is the ability to recognize and name a quantity without counting. Subitizing domino dot, five-frame, ten-frame, and random combinations provides students with visual images that move students from counting to working with quantities as their primary strategy for computing. The phased approach to increase the cognitive demand for some students while giving others the gift of time to build fluency. This approach helps students connect pictorial, verbal, and symbolic representations for the problems they are solving. Manipulative materials can be used to model specific procedures instead of building conceptual understandings. Some materials, such as regular dominoes, have a single representation for each number, one to nine. Other materials, such as ten-frame dominoes, can have a variety of representations for the quantities.
