The study explored the effects of computer use on the mathematical performance of students with special attention to ELL students. To achieve a high generalizability of findings, the study used a U.S. nationally representative database, the Early Childhood Longitudinal Survey Kindergarten Cohort (ECLS-K), and adopted proper weights. The study conducted both cross-sectional and longitudinal analyses to examine the direct and longitudinal effects of three types of computer use: home computer access, computer use for various purposes, and computer use for math. The study found positive effects of home computer access and computer use for various purposes for English-speaking groups. It is important to note that computer use for math was associated with a reduced gap in math achievement between native English-speaking and ELL students. In particular, when Hispanic and Asian students frequently used computers for math, they showed high math performances when compared with their English-speaking counterparts. (Contains 1 figure and 2 tables.)