This study attempted to implement and validate a 5-month effort to transition 42 pupils with mild and moderate disabilities (most with learning disabilities) out of math instruction in special education resource rooms and into regular education math. A preliminary discussion examines the "cascade of services" model and transenvironmental programming as a means of facilitating least restrictive environment student placement. The process utilized computer assisted curriculum based measurement (CBM) to teach math operations in both special and regular education settings. This teaching methodology included goal setting, repeated measurement on goal material, and evaluation of the database to adjust instructional programs. The transenvironmental programming involved four phases: environmental assessment; intervention and preparation; promoting transfer across settings; and evaluation in the mainstream. Evaluation (via a math achievement test, a teacher questionnaire, and CBM data) indicated that experimental students outperformed controls in math achievement and were rated positively by both special and regular class teachers. In addition, whereas all 21 experimental students reintegrated into mainstream math settings either full- or part-time, not a single control student did so. (35 references) (DB)