By handling numbers in unexpected ways, computers and calculators create headaches for computer programers and set traps for unsuspecting users by sometimes producing wrong answers. Specific examples of such computer/calculator errors are discussed. (Author/JN)

Mistakes related to the operation of nuclear power plants and other technologically complex systems are discussed. Recommendations are given for decreasing the chance of human error in the operation of nuclear plants. The causes of the Three Mile Island incident are presented in terms of the human error element. (SA)