In this article, we use multimodality to examine how bilingual students interact with an area task from the National Assessment of Educational Progress in task-based interviews. Using vignettes, we demonstrate how some of these students manipulate the concrete materials, and use gestures, as a primary form of structuring their explanations and making mathematical meaning. We use our results as a basis to challenge the possible deficit perspective of bilingual students' mathematical knowledge in current assessment practices. Choosing tasks that afford multiple modes of engagement and recognizing multimodal explanations in assessment practices has the potential to move us towards a better understanding of what bilingual students know and can do mathematically.