A cup isn't very tall. But what about a lot of cups? Your challenge is to build a tower just made out of cups. How high can you go? Remember, the sky's the limit!

WHAT TO DO

1. Get what you need:
   • Lots of paper or plastic cups (any size works, but it's easier if they're all the same size)
2. Stack some cups: Set one cup directly on top of another. How high can you build before the stack falls over? (No helping by holding the tower up!)
3. Build a tower using the cups: How can you help the cups be more stable? Test out some ideas. Try to make a tall, stable tower that's as tall as you are.
   
4. Take down your tower and build a taller one: Use what you learned from building your towers. Put your cups together in a new way to make a tower that's even taller.

CHEW ON THIS!

Gravity—a tower's worst enemy? Maybe. Gravity can make a tower fall. But it also holds the cups in place! The trick for surviving gravity's pull is to distribute the tower's weight properly. For example, a wide base spreads the weight over a broad area, helping to keep a tower stable. Making sure it's not "top heavy" helps keep a tower from tipping over. And evenly setting the cups upon one another helps the lower cups fully support the upper ones.

DIG DEEPER!

• Build another tower, but change one thing. What about making a wider or a narrower base, or one that is round, square, or triangular? How about using bigger or smaller cups or a mix of sizes? Make a prediction and test it out.
• Make another tower using a different building material, such as coins, marshmallows, or cardboard boxes.
• Like building tall things? Get the Arch, the Financial Support, and the Tall, Sturdy Building challenges from the ZOOM Web site at pbskids.org/zoom/activities.
• Like doing amazing things with paper cups? Get the Paper Cup Walk and the Columns challenges from the ZOOM Web site at pbskids.org/zoom/activities.