These materials were written with the aim of reflecting the thinking of Cambridge Conference on School Mathematics (CCSM) regarding the goals and objectives for school mathematics. Presented are plans for teaching 23 probability lessons in the elementary grades at Hancock School, Lexington, Massachusetts. The discovery approach was utilized by the teacher to involve students in the classroom discussions. Tossing a coin, rolling a die, tossing a thumbtack, and graphing are mediums used in the classroom by students before responding to questions presented by the teacher. The lesson plan for each day is listed. Transcripts of teacher and student statements are included for several lessons. [Not available in hard copy due to marginal legibility of original document]. (RP)