The math story this second grader solves is a change unknown story. There was a full carton of a dozen eggs but when the interviewer goes to make her breakfast there are only three eggs left. She wants to know how many were eaten before she got to the eggs. First he answers one egg. She retells him the story with more details to connect to prior knowledge about egg cartons. He seems to understand the story better. The next time he counts up from the number he knows using his fingers as tools to arrive at the correct answer.
Focus on the Child videos are taken from one-on-one interviews with individual children. The interviews are designed to elicit evidence of children’s mathematical thinking. They are not teaching episodes or formal assessments.