This paper reports preliminary results from a national study of the instructional decisions of experienced secondary mathematics teachers. Using multimedia scenarios of classroom instruction, teachers engaged with different instructional decisions in both geometry and algebra 1 lessons. The results suggest that experienced geometry teachers were likely to act in ways that followed an instructional script, while experienced Algebra teachers seem less likely to do so. These results add nuance to the notion that the instructional scripts are cultural, supporting prior claims that the teaching of mathematics is subject specific.