Science & TechHow it works
How to count to 31 on one hand.
In binary, each digit is worth twice the one before it: 1, 2, 4, 8, 16. The number 1011 means 8 + 0 + 2 + 1 = 11. Your five fingers are five such digits: thumb 1, index 2, middle 4, and so on. All fingers up equals 31, and with both hands you can reach 1023.
Useful: Computers count this way because a switch only knows on or off, yet every number can be built from it.
Source: en.wikipedia.org