Oobleck

Ingredients

• 2 cups cornstarch
• 1 cup water
• color from garden flowers or plant dyes, if we like

Tools

• a large tray or shallow bowl
• measuring cups

Steps

1. Wash our hands with soap and water.
2. Pour the cornstarch into the tray.
3. Add the water a little at a time.
4. Mix it slowly with our hands.
5. Squeeze a handful hard.
6. Open our hand and watch.
7. Tap the top quickly, then press slowly.

Color

• Use water steeped from flowers in place of plain water. No glitter.

Why we use it

Oobleck turns firm when squeezed and runs like a liquid when left alone, so children test it again and again. It asks questions even adults find hard to answer.

I wonder

• I wonder why it feels hard when we squeeze it.
• I wonder where it goes when we open our hand.
• I wonder what would happen if we added more water.

Connections

• Colors from flowers, such as sulphur cosmos yellow.
• Mud outdoors after rain, to compare.
• All year, indoors or outdoors.

Clean up

• Oobleck never goes down the sink, since it can block the drain. Let it dry in the tray and scrape it into the trash.
• Tray and measuring cups. Washed and dried once scraped. Children may help.
• Children wash their hands in a basin first, then at the sink. The educator wipes the table and floor and checks each tool before it is put away.