SureHuntsaLot is correct; it doesn't take 100/10. There are 78.5 sq in in a 10" circle. One pellet/sq in will kill turkeys all day long, provided they are very evenly spaced, which they very rarely are. Thus the oft stated minimum of 100/10. That number provides near 100% confidence when patterns aren't perfectly even.
BTW that standard was conceived by folks on this forum many, many years ago, long before NWTF and the major outdoor rags began to quote it as gospel. And it is a good, conservative minimum IMO.