There is a lack of research examining the use of curriculum-based measurements (CBMs) with special populations, particularly English Language Learners (ELLs). The current study used an alternating treatments single-case design with five Latinx ELL students to examine scores across three math fluency CBM modalities. One-minute probes using either traditional paper-pencil, iPad with a stylus, and iPad with a keyboard were alternated, with students taking two assessments per day. Visual analysis of time-series graphs suggested that most students answered more questions correctly on paper-pencil probes compared to either iPad modalities; scores on iPad with stylus were higher than iPad with keyboard for all students. Non-overlap of all pairs effect sizes indicated small to large differences between probe modalities. All students preferred the traditional paper-pencil probes to either iPad modality. Discussion focuses on the implications for educators using CBMs of different modalities for ELL students.