Oobleck is a fun gooey substance made from a mixture of water and cornstarch. The name “oobleck” came from the Dr. Seuss story Bartholomew and the Oobleck, which is about a kind of slime that could make the whole kingdom gummy. This oobleck isn’t gummy, but is a really cool mix of liquid and solid, acting like a liquid most of the time, unless it squeezed, pressed or punched. Then it acts more like a solid.
I like doing this activity after reading Bartholomew and the Oobleck as a way to enhance what they learned in the story. But even if you don’t read the book, it’s a fun sensory activity that allows them the chance to compare and contrast the oobleck with other textures they already know, and gives them practice using adjectives to describe their experience. (For older kids, oobleck is a great way to teach about non-Newtonian fluid and viscosity.) Here’s what you need:
1 c. water
2 c. cornstarch (add more for thicker oobleck)
1 drop green food coloring (optional)
paper plates, disposable lasagna pan, casserole dish (or any other container you have to contain the oobleck)
1. Mix the water with cornstarch and allow a few minutes for the oobleck to set up. Add food coloring.
2. Let the kids use their fingers to play with oobleck. They can squeeze it, press it, punch it (if safe), let it run through their fingers, etc…
3. While they are playing or after they have finished playing, ask them questions about the oobleck. Below are a few questions I ask during the activity. I’ve also included some of the most common answers. Feel free to add your own!
How does oobleck feel?
Wet, sticky, smooth, slimey, thick, yucky, gooey, like quicksand, etc…
What does oobleck look like?
Slime, goo, white mud, melted chocolate
When did the oobleck feel gooey or slimy?
When I touched it.
When I pushed it around with my fingers.
When it slipped through my fingers.
When did the oobleck feel hard?
When I squeezed it really tight.
When I pressed my hands to the bottom.
When I punched it.
Use soap and water to clean hands. Leftover oobleck can be thrown away and containers rinsed out.