Pluto

The other day a show Nate loves called Little Einstein's was on and they were talking about the planets. They included Pluto, since I guess at the time they show was created Pluto still counted as a planet. So, I started explaining to Grace that there used to be nine planets, however, Pluto is no longer a planet and there are now only eight. Today, for some reason that I cannot remember the subject on planets came up and I wanted to see if Grace had remembered what I had told her the other day. So I asked her, "Grace, how many planets are there?" "

"Eight," she answered.

"How many did there used to be?" I asked.

"Nine," she answered.

"What was the name of the planet that used to be number nine?" I asked.

"Pluto," she answered. "But, now it's a dog."