Last year to jump start our Science Fun we did the color changing milk from Steve Spangler's Website. My students loved it. We did this experiment in small groups with 4 in each group. It's fairly inexpensive with the only cost milk, paper plates, and food coloring. I even purchased the color fizzers from the Steve Spangler website and they were a big hit. I would highly recommend them. If you haven't tried them before they are definitely worth the money. My students also had fun doing the Pinch and Color Mixing Activity from his website too. I have plenty left over to do both of those Steve Spangler experiments again this year.
Another fun experiment with ice cubes is called Color Cubes This is really cheap. We used ice cubes, water, food coloring and clear plastic cups. I made about six trays with red, yellow, and blue ice cubes ahead of time. Then the students worked with a partner and got to experiment many times with different colors to see what would happen as they mixed ice cubes together.
You can download a page that has both experiments and a recording sheet for free on my Teachers pay Teachers store.
I would love for you to link up a share some fun, easy, inexpensive Science Experiments or Science Fun ideas from your classroom.