# How Tall Is Tall?

Here's your nightly math! Just 5 quick minutes of number fun for kids and parents at home. Read a cool fun fact, followed by math riddles at different levels so everyone can jump in. Your kids will love you for it.

# How Tall Is Tall?

July 16, 2014

It’s pretty easy to measure how tall you are: from the floor to the top of your head, no shoes allowed. But your length when you lie down is a little longer, since gravity isn’t squishing you down. Well, height is even more complicated for buildings. The Sears Tower in Chicago, now called the Willis Tower, was the tallest building in the U.S. from 1973 until the World Trade Center Freedom Tower was finished in 2013. But by how much? Do we measure to the top floor, or to the tip of the antenna on top? The Sears Tower has more floors than the Freedom Tower: 108 against 104. But the Sears Tower is shorter: it’s “only” 1,451 feet tall, while Freedom is 1,776 feet tall in honor of America’s birth year. HOWEVER, Freedom Tower’s actual stories rise to only 1,368 feet! A lot of the height is the antenna, and should that count? Either way, the Sears Tower does get one special honor: it has the highest bathroom in the whole Western Hemisphere, at 1,353 feet.

Wee ones: If you ride an elevator for the first 100 floors of the Sears Tower, but climb the last 8 floors by stairs, what numbers do you say to count them off starting with 101?

Little kids: If you added a 1-foot Lego antenna on top of the 1,776-foot-tall Freedom Tower, how tall would it be now?  Bonus: If the Sears Tower has 108 floors and Freedom Tower has just 104, how many more floors does Sears have?

Big kids: If the Sears Tower was America’s tallest building from 1973 until 2013, for how long did it hold that record?  Bonus: If you want to use the Western Hemisphere’s highest bathroom, and the elevator rises 3 feet per second, will you get there in time if you can hold it in for 7 minutes?

Answers:
Wee ones: 101, 102, 103, 104, 105, 106, 107, 108.

Little kids: 1,777 feet.  Bonus: 4 more floors.

Big kids: 40 years.  Bonus: No, because 7 minutes is 420 seconds, in which you’ll travel only 1,260 feet!

### Laura Overdeck

Laura Bilodeau Overdeck is founder and president of Bedtime Math Foundation. Her goal is to make math as playful for kids as it was for her when she was a child. Her mom had Laura baking while still in diapers, and her dad had her using power tools at a very unsafe age, measuring lengths, widths and angles in the process. Armed with this early love of numbers, Laura went on to get a BA in astrophysics from Princeton University, and an MBA from the Wharton School of Business; she continues to star-gaze today. Laura’s other interests include her three lively children, chocolate, extreme vehicles, and Lego Mindstorms.