Mathematics is approached from a developmental framework which begins by utilizing the children's first-hand experiences to form the basis for more sophisticated learning and understanding of mathematical concepts. The goal of the program is to help students make mathematical connections, construct meaning, and further the development of logical thinking skills. Problem solving and critical thinking are emphasized.

The Dalton Mission Statement, the Dalton Plan, and the National Council of Teachers of Mathematics Standards form the basis of the First Program’s mathematics program. The program is divided into the following areas of mathematical learning: Patterns and Algebraic Relationships, Number Sense and Operations, Statistics and Probability, and Geometry, Spatial Sense, and Measurement. Teachers identify and support each student’s thinking and learning style. House Advisors work closely with math specialists to assess individual students and design instruction appropriate to meet individual needs, both for remediation and enrichment. Math instruction takes place daily; students work individually, in small groups or whole groups. Technology resources are also regularly integrated within the program.

By using concrete manipulatives, students are able to develop abstract thinking and to further internalize more complex mathematical concepts. Using carefully constructed math assignments, teachers encourage their students to extend their mathematical awareness. Concepts, skills, and activities provide challenge and a common mathematical language ensures continuity across grade levels.