More than 100 years ago, Orville and Wilbur Wright flew the first airplane. It was all pretty simple: they took off, they crash-landed, they tried it again. Now we have almost 100,000 flights taking off almost every day in the U.S. alone! So it’s very tricky to keep all those planes out of each other’s way. That’s why the guys in the air traffic control tower talk by radio to tell all the pilots where to fly. And thanks to the super-cool website FlightRadar24.com, you can watch all the action yourself. Each blue circle on the map is an airport, and each cute little yellow airplane shows a flight right where it is at this very moment. Don’t worry if you see 2 planes in the same space: all the planes are at different heights above the ground. Still, it’s clearly a big job to direct all that traffic!

*Wee ones:* If 6 planes are lining up to land in New York, and then 1 more flies in line behind them, how many are there now?

*Little kids:* The busiest travel day this month was supposed to be Dec. 23. If today is Dec. 26, how many days ago was that? *Bonus:* If there are 10 planes on the ground, then 3 planes land, then 6 take off, and then 8 new ones land, how many planes are on the ground now?

*Big kids:* If a plane jumps on the screen every 2 seconds, and takes 30 little jumps to cross the map, how long can you watch it “fly” across? *Bonus:* If planes land on *each* of 2 runways every 5 minutes, how many planes do those air traffic guys handle from 2:00 to 4:01 pm, if the first ones land at 2 on the dot?

Answers:

*Wee ones:* 7 planes.

*Little kids:* 3 days ago. *Bonus:* 15 planes: you have 10, then 13, then 7, then 15.

*Big kids:* 60 seconds (1 minute). *Bonus:* 50 planes. Each runway lands one with each of the 12 5-minute chunks in the 1st hour, then the same thing in the second hour, plus the very first at 2 pm (at the start of the first 5-minute chunk). So that’s 12 + 12 + 1, or 25 flights per runway.