Enchanting, multi-layered, and extraordinary in every way, this is a debut novel for children ages 10 and up. Pia loves straight numbers, because they can be divided without breaking them. When Pia first learns about the absolutely imperfect number pi at school and then also has to make friends with her fear element water, she threatens to lose her footing. Tom, of all people, the propeller boy from the swimming pool, offers her support at this moment. For his sake, she even buys a pair of swimming goggles and ventures under water with her head - and suddenly everything makes sense.