The purpose of this study was to examine the measurement properties of the Assessing Math Concepts AMC Anywhere Hiding and Ten Frame Assessments, formative assessments of primary students' number sense skills. Each assessment has two parts, where Part 1 is intended to be foundational skills for part two. Part 1 includes manipulatives whereas Part 2 does not. Student data from 228 kindergarten through second grade teachers with a total of 3,666 students was analyzed using Rasch scaling. Data analyses indicated that when the two assessments were examined separately the intended order of item difficulty was clear. When the parts of both assessments were analyzed together, the items in Part 2 were not consistently more difficult that the items in Part 1. This suggests an alternative sequence of tasks in that students may progress from working with a specific number with manipulatives then without manipulatives rather than working with a variety of numbers with manipulatives before moving onto assessments without manipulatives.