Developing a Vertically Scaled Assessment of Elementary Students’ Number Sense

This article advances an argument-based approach to presenting validity evidence for a brief assessment of 3 rd –5 th grade students’ number sense. Improving students’ number sense has been a goal of K-12 mathematics education in the US since the late 1980’s, and several popular instructional practices are hypothesized to meet this need. However, there is limited evidence in the literature that elementary students’ number sense is improving. We worked to develop a brief assessment for 3 rd –5 th grade students and then conducted a series of studies to collect evidence that students’ scores reflect their number sense. We present the assessment here along with our intended interpretations and ways to use student scores. We then outline our validity argument, organized by four specific claims addressing the connection between student responses on the assessment and their number sense. Researchers and educators can now use the assessment to efficiently measure elementary students’ number sense.