Good Eye!

Today, I helped Daniel practice his piano. One of the activities was flash cards with the notes in each staff. When I showed him the F in the lowest space of the treble clef, he enthusiastically said, "E!" I quietly said, "no." He almost immediately responded by telling me it would be an E if I turned the card upside down (thus placing the note in the top space in the treble clef, an E). I hope I don't do anything that makes him lose that ability.