A child approximates the number of cubes in collections of increasing quantity. After guessing big number words such as “thousand” and “hundred,” she looks for smaller groups within the larger set. Her estimate of three groups of seven is quite accurate. (There are 27 cubes.)
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.