Promoting Decimal Number Sense and Representational Fluency

Abstract

The abstract nature of mathematics requires the communication of mathematical ideas through multiple representations, such as words, symbols, pictures, objects, or actions. Building representational fluency involves using mathematical representations flexibly and being able to interpret and translate among these different models and mathematical concepts. This article shares a collaborative lesson study experience in planning and teaching a unit on decimals. Participants included fifth- and sixth-grade teachers and lesson study facilitators, including a university mathematics educator, a doctoral student, and a school mathematics specialist. The lesson was taught in a fifth-grade class with a high population of English language learners (ELL) and special needs students. The overarching goal of the lesson study was to develop students' representational fluency and mathematical proficiency with decimals. While working with teachers, the lesson study facilitators shared related research on representations and the importance of selecting and evaluating effective mathematical models to give the diverse population access to decimal concepts. The lesson study facilitators' goal was to heighten teachers' awareness of the importance of multiple representations and introduce a planning process that allows teachers to select models in a thoughtful and critical way that would facilitate the teaching and learning of a mathematics concept.