The intent of this study is to determine whether or not teaching students how to use available calculators can improve their mathematics test scores. The study involved 89 seventh and eighth grade students. These students were randomly divided into three separate groups which included two experimental groups and the control group. The control group did not use calculators while one experimental group had access with no instruction on how to use them and the other experimental group had access with instruction. The design for this investigation was an experimental, three-group, pre-test/post-test design. The data were analyzed using a t-test of gain scores. The calculator used for this investigation was the Texas Instrument Math Explorer Plus. All three groups took a pre-test without the use of a calculator. Both experimental groups took the post-test two weeks later with the use of a calculator but one group had classroom instruction on how to use the calculators first. The results showed that at the end of the two-week period the test scores improved significantly when calculator instruction was given. Although test scores improved when students had access to calculators without instruction, there was no significant difference statistically. This indicates that students should be properly instructed on the use of calculators during classroom situations before using them in testing situations. (Contains 49 references.) (Author)