Paper Folds
กระดาษหนา 0.1 มม. พับทีไรหนาขึ้นสองเท่า · ทายว่ากี่ทบถึงยีราฟ เอเวอเรสต์ หรือดวงจันทร์
กระดาษแผ่นหนึ่งหนาเพียง 0.1 มม. แต่การพับแต่ละครั้งจะทำให้ความหนาเพิ่มเป็นสองเท่า ความสูงของกองจะเพิ่มขึ้นเร็วแค่ไหน?
คุณต้องพับกระดาษกี่ครั้งจึงจะสูงเท่ากับ ยีราฟ?
ทำไมถึงใช้น้อยจัง: การเพิ่มเป็นสองเท่าเติบโตอย่างรวดเร็วอย่างไม่น่าเชื่อ · การพับ 42 ครั้งของกระดาษหนา 0.1 มม. จะถึงดวงจันทร์
About Paper Folds
Paper Folds is a small lesson in how fast doubling runs away from you. A sheet of paper is about 0.1 mm thick, and every time you fold it in half the thickness doubles. The game names a real object · a giraffe, the Eiffel Tower, Mount Everest, the Moon · and asks how many folds it would take for the stack to reach that height. Four choices; pick the closest.
The answer is exact maths, not a guess. The number of folds is the smallest whole number of doublings that reaches the target height: ceil(log2(height ÷ 0.1 mm)). Because the growth is exponential, the answers are absurdly small · a giraffe takes about 16 folds, Everest about 27, and the Moon a mere 42. The reveal shows the object's real height and the fold count every round.
Build a streak. Each correct answer grows your streak and your best is kept, so a run trains your intuition for exponential growth · the same maths behind compound interest and viral spread.
Part of the PlayMemorize family · runs entirely in your browser and works offline as a Progressive Web App.
FAQ
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How is the number of folds worked out?
A sheet of paper is 0.1 mm thick and every fold doubles it, so the height after n folds is 0.1 mm times two to the power n. The answer is the smallest whole number of folds whose stack reaches the target height · mathematically, the ceiling of log base 2 of the height divided by 0.1 mm. -
Does folding paper 42 times really reach the Moon?
In theory, yes. 42 doublings of a 0.1 mm sheet is about 440,000 km, which clears the average Earth-Moon distance of roughly 384,400 km. In practice you cannot fold ordinary paper more than about seven or eight times · the game is about the maths of doubling, not a folding challenge. -
Are the object heights real?
Yes · they are the widely-cited real heights or distances for each object, from a giraffe at about 5.5 m to the edge of space, the Space Station and the Moon. The reveal shows the height it used. -
Why do such tall things need so few folds?
Because doubling is exponential. Ten folds already gives about a metre, twenty folds about a kilometre, thirty folds about 1,000 km · each ten folds multiplies the height roughly a thousandfold, so even huge heights fall within a few dozen folds. -
Does it work offline?
Yes. PlayMemorize is a Progressive Web App, so Paper Folds keeps working without a connection once the page has loaded.