What do you see all around your room? Walls. Houses and buildings have walls, and so do many cities. They built giant walls around themselves to keep out enemies. But the longest, widest wall of all is the Great Wall of China. It runs halfway across the whole country, and since it’s 16 to 20 feet wide, cars and people can travel on top of it. So our fan Scout B. asked, how long is the Great Wall? It zigzags through the mountains, because it connects pieces of wall built hundreds of years apart. But if you straightened it out, it would stretch 3,889 miles. When you add in the trenches (deep, wide holes that people couldn’t cross) and rivers, it covers 5,500 miles! That’s more than twice as long as the U.S. How many houses could be built from that amount of wall? When we do the math, the number is surprising.
Wee ones: How many walls does your room have? Do any rooms in your home have more than that?
Little kids: The Great Wall is 20 feet wide at the bottom and 16 feet wide at the top. Is it wider at the top or bottom? Bonus: The Great Wall is about 25 feet high in many places. If your ladder reaches 1 foot higher, how high does your ladder reach?
Big kids: If a house is a 50-foot-wide square, how long are its 4 walls put together? Bonus: Let’s say you can make 20 full houses from 1 mile (5280 feet) of wall. How many houses can you make from 4,000 miles of Great Wall walls? (Hint if needed: What if you could make just 2 houses from each mile of wall?)
Wee ones: Different for everyone…most closed-in rooms have 4 walls, but if 1 side is open, it might have just 3. Or it might not be a rectangle!
Little kids: Wider at the bottom. Bonus: 26 feet.
Big kids: 200 feet. Bonus: 80,000 houses!