Finger binary

Finger binary is a system for counting and displaying binary numbers on the fingers of either or both hands. Each finger represents one binary digit or bit. This allows counting from zero to 31 using the fingers of one hand, or 1023 using both: that is, up to 2⁵−1 or 2¹⁰−1 respectively.

Modern computers typically store values as some whole number of 8-bit bytes, making the fingers of both hands together equivalent to 1¼ bytes of storage—in contrast to less than half a byte when using ten fingers to count up to 10.

In the binary number system, each numerical digit has two possible states (0 or 1) and each successive digit represents an increasing power of two.

Note: What follows is but one of several possible schemes for assigning the values 1, 2, 4, 8, 16, etc. to fingers, not necessarily the best. (see below the illustrations.): The rightmost digit represents two to the zeroth power (i.e., it is the "ones digit"); the digit to its left represents two to the first power (the "twos digit"); the next digit to the left represents two to the second power (the "fours digit"); and so on. (The decimal number system is essentially the same, only that powers of ten are used: "ones digit", "tens digit" "hundreds digit", etc.)

It is possible to use anatomical digits to represent numerical digits by using a raised finger to represent a binary digit in the "1" state and a lowered finger to represent it in the "0" state. Each successive finger represents a higher power of two.

With palms oriented toward the counter's face, the values for when only the right hand is used are:

When only the left hand is used:

When both hands are used: