When teachers conduct a universal screening in mathematics, they identify students who are struggling with mathematical content and adjust their instruction. In this mixed-methods study in Kolkata, India, teachers piloted a screening tool at the beginning of the academic year in 5th grade to determine students' (n = 171) understanding of fractional number sense. The results of the screening show that the majority (70%) of students in fifth grade are in need of more instruction in foundational fraction concepts. Common misconceptions on screener items are shared, as well as strategies for improving fraction instruction to prevent future errors.