  As educational systems move from onsite to online due to the COVID-19
pandemic, teachers face the difficulty of designing online examination formats
which minimise opportunities for dishonesty. In this paper, we expose our
design of such a format: a protected Microsoft Excel spreadsheet containing
short-answer questions, which was implemented in a calculus module taught by
us. This format allows examiners to randomise questions with the aim that each
student receives each question with different numerical details, making
plagiarism impossible, while keeping the marking effort very low.
