When Katy is giving her presentation Maya is in different positions in her chair nearly every time the camera shows the class with little to no time in between shots.
While the Matthews family is eating dinner, the salt shaker is visible in Auggie's shirt pocket before the family starts talking about Cory's talent in close up magic.
When Topanga's shaking her hips, the chair she was sitting on is leaning against the cabinet behind it. In the next shot, the chair is upright behind her and then back to its original position again.