Without #students, #classrooms are empty-physically, culturally, contextually, pedagogically. The idea one can meaningfully plan a class before meeting the students seems disingenuous.
A blog post, now with audio, describing two math activities:
https://hackscience.education/2018/09/22/a-disturbing-observation/
Director of Teaching and Learning Innovation at a community college in New England
Retired k-12 science/ math/ technology teacher/ technology integration specialist/ coordinator