Books in the Alex, the Inventor series

Alex hears balloon flower buds popping. She is sure the plants are talking to her.  She invents a plant translator. The plants want to have a party. They want to fly. She invents a flower inflator. The plants want her to fly with them. It's fun until the plants try to talk to her while flying and when they pop, the helium comes out of their flowers, so they come back to Earth. Now they want Alex to invent a way for them to talk and fly at the same time.  She's had enough inventing for one day.

Alex hears balloon flower buds popping. She is sure the plants are talking to her.  She invents a plant translator. The plants want to have a party. They want to fly. She invents a flower inflator. The plants want her to fly with them. It's fun until the plants try to talk to her while flying and when they pop, the helium comes out of their flowers, so they come back to Earth. Now they want Alex to invent a way for them to talk and fly at the same time.  She's had enough inventing for one day.