Stairway to the Moon

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.

Stairway to the Moon

October 18, 2018

Our Moon is bigger than you think. It may look small, but it’s about 2,000 miles across, the same width as the US from Florida to California! The Moon looks teeny only because it’s a quarter million miles away. So our fan Quinn F. asked, how many stairs would you need to walk to the Moon? Well, you’re climbing 240,000 miles, which is more than 1 billion feet (1,267,200,000 feet), or about 15 billion inches. House stairs are supposed to be 7 3/4 inches tall at most. So you need 1,962,116,129 steps — almost 2 billion stairs to climb that high! The problem is, stairs are also 10 inches from front to back. So those stairs would start 310,000 miles way over to the side. You’d have to fly into outer space just to start climbing!

Wee ones: Look out the window. Do you see any space objects right now, like the Moon, Sun, or stars? What shapes do you see?

Little kids: If you climb steps 2 at a time, after the 2nd, 4th and 6th which step do you touch next?  Bonus: Once you’ve jumped to the 10th step, how many have you touched in total?

Big kids: Can you “spell” 2 billion as a number, without looking at the numbers above?  Bonus: If you can climb 100 steps in a minute, how many minutes would it take to climb the 2 billion steps to the Moon?

The sky’s the limit (for real): While the Moon is 1/4 million miles away, the Sun is 93 million miles away. If you need 2 billion steps to reach the Moon, how many do you need to reach the Sun? (Hint if needed: How many do you need to climb 1 million miles?)











Wee ones: The Sun always looks like a circle; the Moon can be a circle, a gibbous shape (circle with one edge shaved off), a half circle, or a crescent (C shape); stars look like tiny circles.

Little kids: The 8th step.  Bonus: 5 steps.

Big kids: 2,000,000,000.  Bonus: 20 million minutes, which is 13,889 days, or 38 years!

The sky’s the limit (for real): 744 billion steps. You need 8 billion steps for each million miles, then need 93 times that number to reach the Sun.

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About the Author

Laura Overdeck

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 before she could walk, 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.

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