How do they easyCBM percentile math test scores compare to MAP test scores>

We have not run any studies comparing the easyCBM scores to the scores from the MAP assessments, although we would be happy to run the analyses if a district wanted to supply us with de-identified data that includes scores on both measures. We have run an analysis of the relation between easyCBM and Smarter Balanced assessments. That info can be found at:

The Relation Between Smarter Balanced and easyCBM Mathematics and Reading Assessments
This study investigated the relation between the easyCBM Benchmark Assessments in both mathematics and reading and the Smarter Balanced assessment, widely adopted across the United States. Alonzo, J. Journal of School Administration Research and Development. 2016;1(1):p17-35. https://eric.ed.gov/?id=EJ1158121