Finger binary

It is also possible to have each hand represent an independent number between 0 and 31; this can be used to represent various types of paired numbers, such as month and day, X-Y coordinates, or sports scores (such as for table tennis or baseball).

Representing negative numbers is extremely simple, by using the leftmost finger as a sign bit: raised means the number is negative, in a sign-magnitude system.

If a convention were reached on palm up/palm down or fingers pointing up/down representing positive/negative, you could maintain 210 −1 in both positive and negative numbers (−1,023 to +1023, with positive and negative zero still represented).

The simplification process can itself be greatly simplified by performing a bit shift operation: all digits to the right of the rightmost raised finger (i.e., all trailing zeros) are discarded and the rightmost raised finger is treated as the ones digit.

The index finger's original value (1/4) determines the denominator: the result is 3/4.

Combined integer and fractional values (i.e., rational numbers) can be represented by setting a radix point somewhere between two fingers (for instance, between the left and right pinkies).

Dyadic fractions, explained above, have limited use in a society based around decimal figures.

A simple non-dyadic fraction such as 1/3 can be approximated as 341/1024 (0.3330078125), but the conversion between dyadic and decimal (0.333) or vulgar (1/3) forms is complicated.

Instead, either decimal or vulgar fractions can be represented natively in finger binary.

Decimal fractions can be represented by using regular integer binary methods and dividing the result by 10, 100, 1000, or some other power of ten.

19 in finger binary: the pinkie finger is 16, added to the 2 of the index finger and the 1 of the thumb
3/4, in fractional finger binary