Hi Brianna! First, I taught them the 'My Very Excellent Mother Just Served Me Nine Pizzas' then took away the Pizzas. Then we did a scale model of the solar system on the gym floor. I had some pictures of the planets with a description on each. Here's a calculator http://www.exploratorium.edu/ronh/solar_system/
Then, I taught the kids how to make a paper airplane to show aerodynamics. This was their 'rocket.' They took turns to see how far their rocket would go. When it landed, I had them read the description of the planet. It wasn't too long before they knew Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto. Then we talked about the story behind Pluto and took it away.