Pea geometry? This is such a fun craft which I learned after Wille brought some home from school when he was about six or seven. All you need are dry yellow peas and cocktail/toothpicks. Check this out:
After soaking the dry yellow peas over night in a bowl with water you can simply poke them with toothpicks.
After the initial one you just keep adding toothpicks. Be careful not to poke then too deep though so the pea doesn't split.
Yay, it's Friday! Happy weekend!