You didn't read the part about gravity being a force pulling you to the center of the Earth. There is no "upside down." Everywhere on Earth, toward the sky is "up" and toward the ground is "down." Yes, it is amazing that any 5th-grader is more advanced than you are.
Good irony, since the rotational acceleration of the Earth is so small as to be undetectable by human beings. (Do the math.)
It's called gravity. A force attracting objects to the center of mass of the Earth. You might have experienced it.
Look, you really need to get up to the level of 5th grade science. Ignorance like this is embarrassing.
You didn't read the part about gravity being a force pulling you to the center of the Earth. There is no "upside down." Everywhere on Earth, toward the sky is "up" and toward the ground is "down." Yes, it is amazing that any 5th-grader is more advanced than you are.