Ternary numeral system

As for rational numbers, ternary offers a convenient way to represent ⁠1/3⁠ as same as senary (as opposed to its cumbersome representation as an infinite string of recurring digits in decimal); but a major drawback is that, in turn, ternary does not offer a finite representation for ⁠1/2⁠ (nor for ⁠1/4⁠, ⁠1/8⁠, etc.

A rare "ternary point" in common use is for defensive statistics in American baseball (usually just for pitchers), to denote fractional parts of an inning.

[2][3] Ternary numbers can be used to convey self-similar structures like the Sierpinski triangle or the Cantor set conveniently.

It is also used to represent three-option trees, such as phone menu systems, which allow a simple path to any branch.

A form of redundant binary representation called a binary signed-digit number system, a form of signed-digit representation, is sometimes used in low-level software and hardware to accomplish fast addition of integers because it can eliminate carries.

If the trit values 0, 1 and 2 are encoded 00, 01 and 10, conversion in either direction between binary-coded ternary and binary can be done in logarithmic time.

[10] Some ternary computers such as the Setun defined a tryte to be six trits[11] or approximately 9.5 bits (holding more information than the de facto binary byte).

Use of ternary numbers to balance an unknown integer weight from 1 to 40 kg with weights of 1, 3, 9 and 27 kg (4 ternary digits actually gives 3 4 = 81 possible combinations: −40 to +40, but only the positive values are useful)