This study investigated the effects of the use of hand-held calculators on problem solving and computational skills of elementary school students. It also considers the resulting implications for curriculum change. Evaluation focused on achievement in problem solving, computational skills, and number concepts of kindergarten, second grade, and fourth-grade students. The investigation examined differences in achievement test scores in mathematics of the experimental group which used calculators and the control groups which did not use calculators. The experimental group scored significantly higher than the control group in kindergarten. The data seem to indicate that there is no significant difference in achievement between the experimental and control groups in second and fourth grade. This seems to indicate that calculator use has no detrimental effect on mathematics achievement at these grade levels. An attempt to access parent attitudes was also made. Results of this questionnaire are reported. Appendices A, B, and C contain suggested calculator activities for kindergarten, second grade, and fourth grade, respectively. The parent questionnaire and various tabulations of responses to it make up the remainder of the appendices. (Author/MK)