The “oddness” of prime numbers is driven home in this delightful tale of two bugs and their bean dinner. On a foraging expedition, Flora insists on picking just one more, even though Ralph is vehemently against having 13 beans, an unlucky number. The two perfect piles, and the one leftover bean, seem to prove him correct. But Flora is quick with a solution; call a friend and divide the beans into three even piles. Still one bean is leftover. More and more friends are invited, but that unlucky bean remains. What’s the solution? Serve the beans family style. Flora invites the guests to take what they wish, and every bean is eaten. The only question left for Ralph is, “Who ate bean thirteen?” McElligott’s imaginative pen-and-ink-and-digital illustrations feature brilliant hues and humorous bugs with a large vocabulary of body language. Pair this one with Elinor J. Pinczes’s A Remainder of One (1995) to show just how unique prime numbers are. A must for every elementary-school library and classroom bookshelf. (Picture book. 4-8)