The Riddle
Consider this riddle I found spreading on Facebook some while ago.
This problem can be solved by children in five to ten minutes, programmers in an hour and people with higher education…
8809 → 6 5555 → 0
7111 → 0 8193 → 3
2172 → 0 8096 → 5
6666 → 4 1111 → 0
3213 → 0 9999 → 4
7662 → 2 7756 → 1
9313 → 1 6855 → 3
0000 → 4 9881 → 5
2222 → 0 5531 → 0
3333 → 0 2581 → ?
I solved it pretty quickly. Why don’t you try?
Have you seen the Bollywood film 3 Idiots? Here’s the funny space pen scene from it.



True story or not, this scene propones the folly of complex solutions to simple problems. How many times have we caught ourselves inventing space pens?
Children we once were, growing up was largely about maturing psychologically into adults. Responsibility, paying the bills, getting things done and various complexities we call adulthood. To come of age was to lose our tantrums, silliness and innocence. Hence started the displacement of our childly minds.
The artless mind of a child is our greatest gift. As embryos in our mothers, our heart is the first organ to develop only to power the next – the seedling brain which will eventually make a quarter of a million new neurons every minute. By the age of ten, each of us would have made billions and billions of neural connections. It is a supercharged engine for learning and creativity. Yet by adulthood we would have displaced most of this creativity. The adult mind thinks too much. Its thoughts too influenced by knowledge. We must regain the ability to think like kids again.
Quora is a knowledgeable community. Admist the clever answers one often finds overthinking and complication from people triyng to look smart. How would you cut a pizza into 11 pieces?
The popular answers to the question involved calculations with compasses, concentric circles, Pythagorean theorem and square roots until someone suggested a solution using strings, something not hard to find in a kitchen. I had no idea what a concentric circle is, let alone pizza cooks. And who keeps compasses in a kitchen?
The simple string solution involves first circling then cutting a string around the pizza’s circumference. The string is then wrapped eleven times around one’s thumb and index finger until one gets eleven equal divisions by trial and error. The divisions are then marked. Circle the string around the pizza again and cut from center to the markings. What simplicity! The answer soon became a rated as best source.

Conjuring mathematical mumbo jumbo may make one look smart. To be truly creative one needs to be able to liberate the mind from accumulated grown-up banality. Only then the child mind re-emerges.
Answer to the numbers question
The question has nothing to do with mathematics. Look for the closed loops or shapes in each number and count them. In 0, 6, 8 and 9. 8 has two of them. 2581 has two. The answer is 2.
First published in my old website and featured on Lifehacker.