One hundred twenty-eight undergraduates were randomly assigned to one of four treatment conditions formed by crossing two levels of task difficulty (computationally easy or difficult problems) with two modes of calculation (solving by hand or calculator). When solving problems by hand, there was a large increase in state anxiety between easy and difficult problems. However, level of anxiety experienced on easy problems solved by hand was not lower than the difficult problems solved with the aid of a calculator. Results of this study provide additional evidence for the benefits of using calculators, particularly as problem difficulty increases. (Author)