This paper documents the achievement monitoring component of a three-year study on the acquisition of addition-subtraction problem-solving skills by young children. A set of performance objectives contained in or ancillary to ten instructional units on sentence-writing for verbal problems and algorithms specified test content. Tests measuring group progress toward these objectives were administered after each unit. Data for the tests given after the two units covered in the spring semester of grade 2 (n=120) are described. This paper presents (1) background information on the subjects and instructional materials, (2) a description of the three-year achievement monitoring plan and the tests, (3) a report of the data collection procedures, and (4) a discussion of the results. Samples of the tests, administrator's manuals, and complete item and test statistics appear in the appendices. (PN)