Evan and his younger sister, Jessie, react very differently to the news that they will be in the same class for fourth grade and as the end of summer approaches, they battle it out through lemonade stands, each trying to be the first to earn one hundred dollars. Evan y su hermana menor, Jessie, reaccionan de manera muy diferente a la noticia de que van a estar en la misma clase de cuarto grado y como el final del verano se acerca, ellos luchan hacia...