The Mysterious City of El Numero Tribes "--Provided by publisher

"--Provided by publisher

a Scottish mathematician and astronomer

con artists

alter the military balance

They say she jumped from a bridge and plunged over twenty feet to the train tracks below

The Mysterious City of El Numero Tribes "--Provided by publisherDaisy and Dale's father, adventurer Darren Deed, has gone missing during a mission to South America. After the kids receive a mysterious package in the mail, clues unravel that might lead to his whereabouts. He's possibly in the mysterious city of El Numero. Daisy and Dale need readers' help, and math skills, as they attempt to rescue their father. This clever volume seamlessly combines an exciting adventure story with need to know math concepts and