According to Every Student Succeeds Act, schools are accountable for the improvement of all children; including those with disabilities or difficulties, recently arrived English language learners (ELs) as well as long-term ELs, and all students for whom English is not their native language. To meet the accountability requirements, it is essential to provide both linguistic scaffolds and content-specific interventions to address these students' achievement gaps in mathematics. Using a single-subject design, the purpose of this study was to evaluate the effect of computer-assisted "Conceptual Model-based Problem Solving" (COMPS) tutor on additive word problem-solving performance of ELs with learning difficulties in mathematics. Findings indicate that all four participants improved their performance on researcher-developed criterion test as well as a generalization test following the intervention. It seems that features such as conceptual model-based visual scaffolding and linguistic scaffolding found in the COMPS tutor, may have contributed to students' access to learning mathematics and the positive outcome of this study.