Capacity Building of Teachers in Mathematical Communication in The Classroom through Lesson Study Approach on Mathematics Teachers

Lesson Study approach can improve the capability of teachers in mathematical communication in the classroom with the results: 1). There is increased activity in the Lesson Study from 65% at early stage to 72% in cycle 1 and the final stage to 78%, 2). There is an increased capability of teachers in mathematical communication in the classroom of 51% on the early stage increased to 66% in cycle 1 and the final stage to 75%, 3). There is a learning outcome improvement in the early stage of 59% increased to 80% in cycle 1 and the final stage to 88%. Keywords- Teacher Capability, Mathematical Communications, Lesson Study Approach.