This article shows how to modify classroom evaluation items to avoid four potential difficulties that limit a teacher's insight into students' mathematical understanding by addressing these issues: (1) poor choice of numbers; (2) implausible or inappropriate contexts; (3) inclusion of graphics that do not help make learning visible; and (4) assumptions needed to answer the items. The authors identified these issues as part of a research project to analyze the influence of the mathematical Process Standards in classroom tests (106 tests from their early work from 2003 to 2005 and 15 tests from three 2010-2011 textbook series mentioned herein.) By critically looking at items, considering the issues highlighted here, and discussing curriculum assessments with peers, teachers can become sensitized to potential difficulties with items before using them. Teachers can then modify the items to better assess student learning instead of waiting until after an assessment has been administered to realize that several items failed to generate useful information about student learning. (Contains 1 figure.)