In recognition of the fact that young children develop informal number concepts and strategies for solving several basic types of verbal addition and subtraction problems before entering school, but lose this ability after a few years of schooling, the study created and tested an intervention designed to build on the children's early insights. A plan was developed for initial instruction in verbal problem solving that would measure the effects of teaching children to symbolically represent verbal problems with number sentences that directly modeled verbal problem structures. The plan was based on a review of concrete and symbolic representation in mathematics and canonical or noncanonical categories of number sentences to represent various categories of verbal addition and subtraction problems. A pretest treatment, posttest design was used. The subjects (N=45) were two first-grade classes in a rural area outside Madison, Wisconsin. Evaluation of the pretest-posttest differences showed that the children made significant gains both in solving verbal problems and in writing correct number sentences. Appendices include the problem classification scheme, problem form or type, actual pretest and posttest, and analyzed results. A five-page reference list is included. (JM)