Jane Watson and Lyn English use a chance activity exploring expectation and variation with coin tossing to highlight the importance of understanding the part-whole relationship embodied in percentage and its power to measure and compare for different wholes, in this case different sample sizes. The purpose of this article is to raise awareness of the opportunities to distinguish between the use of raw numbers and percentages when comparisons are being made in contexts other than the media. It begins with the authors' experiences in the classroom, which motivated a search in the literature, followed by a suggestion for a follow-up activity.