BRT Math Screening Measures focus on students' mathematics performance in grade-level standards for students in grades 1-8. A total of 24 test forms are available with three test forms per grade corresponding to fall, winter, and spring testing periods. Each form contains computation problems and application problems. BRT Math Screening Measures were administered to 6,500 students during the 2006-07 school year. The Rasch Model in Item Response Theory (IRT) is employed to estimate the item difficulties and fit statistics of the test items. We describe this process and then present results of item difficulty and item functioning. (Contains 26 tables.)