As part of a federally funded grant, we conducted Math for All professional development workshops at elementary schools in the Midwest to support teachers' implementation of high-quality, standards-based mathematics education for a wide range of students, including those with disabilities. Our research included week-long instructional logs administered during the 2019-20 and 2020-21 school years. These instructional logs from a small sample of K-5 teachers (n=22 at three rural districts, and n=53 at one urban district) help describe the nature of mathematics instruction and teachers' lesson planning practices prior to the COVID-19 crisis (October 2019-early March 2020) and during the pandemic (April-May 2020 and during the 2020-21 school year). Our findings demonstrate the need for more support for teachers in the areas of lesson planning and differentiating instruction to enable them to be more flexible and to be better prepared to address diverse students' needs under challenging instructional conditions.