There are generally 4 ways to change the value of a number field:
Typing the value will directly override it.
Clicking the arrow buttons will change the value by the provided step value (0.1, 0.01, etc.)
Scrolling with the mouse wheel while the cursor is over the input field and the field has focus will change the value by the provided step value (same as the arrow buttons.)
Pressing the up or down arrows on the keyboard while the field is in focus will change the value by the provided step value (same as the arrow buttons.)
Empty objects have the ability to "move without affecting children".
This helps with the use case when you want to use an empty object as a parent pivot for animating a group of children.
It can be activated by clicking the icon next to the Position properties, this will allow you to use the gizmo to move the empty object, without moving the children it contains.