In the course I'm currently teaching, we're testing our understanding of elementary school arithmetic algorithms by working in base 5. Each day, I write up several example problems for them to try along with the answer (so that they'll know if they've gone awry). Invariably, if I churn out a list of twenty practice problems by hand, one or two of my answers are wrong. This is frustrating to both me and the student, since they always double and triple check their work before daring to ask if I've made a mistake. In order to check my work before this happens, I wonder:
Is there a simple program (either online or in Maple/Matlab) for performing arithmetic in alternate bases?