Duck Soup by Jackie Urbanovic: (Pre-K through 4th)
Maxwell Duck is trying to invent a soup that everyone will remember him for, but when he goes out to look for the missing ingredient and his friends show up, they think he has fallen into the soup.

Skippyjon Jones and the Big Bones by Judy Schachner: (Pre-K through 4th)
Holy guacamole! Skippyjon is crazy-loco for dinosaurs! The kitty boy enters (via his closet) the land of dinosaurs in search of the fabled skipposaurus. Instead he runs into his old amigos, the Chimichango gang. When a T-Mex threatens the pack, it's El Skippito, the great sword fighter, to the rescue. With yips and yowls, he drives the big baddie away, so all the dino-dudes can rattle their bones another day.

The Batboy by Mike Lupica (3rd-4th)
Brian Dudley has every baseball kid's summer dream job: he is batboy for his hometown's major league team, the Detroit Tigers. Even more exciting, his hero, Hank Bishop, is returning to the sport after a 50-game suspension to play for the Tigers. This could be the year Bishop hits his 500th homerun---the elusive goal for all hitters that almost guarantees a place in the Baseball Hall of Fame--and Brian will be on the field to see it. But Bishop seems to dislike Brian from the very start.
The Missing Series by Margaret Peterson Haddix (4 books): (3rd -4th)
Book 1: Found:
One night a plane appeared out of nowhere, the only passengers aboard -- thirty-six babies. As soon as they were taken off the plane it vanished. Now, thirteen years later, two of those children are receiving sinister messages, and they begin to investigate their past. This story will take you hurtling through time -- from the far past to the distant future.
Book 2: Sent:
Jonah, Katherine, Chip, and another boy, Alex, have no preparation before they are sent back to 1483 at the tower of London, with the promise that they can return to the present if they can repair history. They quickly discover that Chip and Alex's true identities are the thirteen-year-old King Edward the V and his 10-year old brother, Richard, The Duke of York.But before Chip can enjoy being the King of England, they discover that they are virtually prisoners-and that their uncle wants them dead. How can the kids repair time and return home when according to history, Chip and Alex were murdered?
Book 3: Sabotaged:
After helping Chip and Alex survive 15th century London, Jonah and Katherine are summoned to help another missing child, Andrea, face her fate. Andrea is really Virginia Dare, from the Lost Colony of Roanoke. Jonah and Katherine are confident in their ability to help Andrea to fix history, but when their journey turns dangerous, they realize they may be in over their head. They've landed in the wrong time period. Andrea doesn't seem that interested in leaving the past. And even worse, it appears that someone has deliberately sabotaged their mission....
Book 4: Torn:
Still reeling from their experiences in Roanoke in 1600, Jonah and Katherine arrive in 1611 only moments before a mutiny on Henry hudson's ship in the icy waters of James Bay. But things are messed up: they've lost the real John Hudson, and they find what seems to be the fabled Northwest Passage- even though that they are pretty sure that route doesn't exist.