This comment reflects Fatima’s Common Content Knowledge associated with whether
an equation was necessary to characterize factor-based change (or whether it sufficed for
students to say that for three times as many people the shares are one-third of the initial
size). It also reflects how she used her own approach to the task to learn the concept of this
LT level. Her contribution raised a question and also initiated a discussion about what an
equation for factor-based change would look like.