AdditionGrace Lisa Vandenburg counts. The letters in her name (19). The steps she takes every morning to the local caf (920); the number of poppy seeds on her slice of orange cake, which dictates the number of bites she'll take to finish it. Grace counts everything because numbers hold the world together. And she needs to keep an eye on how they're doing. Seamus Joseph O'Reilly (also a 19, with the sexiest hands Grace has ever seen) thinks she might be better