This study takes an in-depth look at one student who is on the autism spectrum with severe language delay and who received focused instruction in mathematics over a 5-month period for 52 sessions. Twenty-nine of these sessions included instruction around division. The strategies and representations for division emerging during these 29 sessions were analyzed and mapped onto the iceberg model (Dekker, 2007), thus providing a visual of the child’s development of understanding. This study indicates that being attuned to student thinking and using the concrete to abstract continuum as a frame to structure the learning sequence supported this child’s growth in division of numbers under 100, beginning with the basic facts. Although the amount of time required to reach this level of understanding was extensive, the learning process was parallel to that of general education students.