We use thematic analysis to explore how mathematical concepts are developed in four enactments of the same task. Thematic analysis emerges from Systemic Functional Linguistics and provides a means to explore the development of mathematical ideas in the classroom discourse. Thematic analysis was used to explore how themes related to the comparison of like quantities were developed in a task designed to introduce different types of comparisons and different ways to represent comparisons. The thematic analysis showed similarities across the four teachers' enactments, suggesting an influence from the design of the task. There were also differences that pointed to teachers' different emphasis and their own understanding of the thematic pattern. [For the complete proceedings, see ED597799.]