Digit (unit) in the context of Turin

The foot (standard symbol: ft) is a unit of length in the British imperial and United States customary systems of measurement. The prime symbol, ′, is commonly used to represent the foot. In both customary and imperial units, one foot comprises 12 inches, and one yard comprises three feet. Since an international agreement in 1959, the foot is defined as equal to exactly 0.3048 meters. The most common plural of foot is feet. However, the singular form may be used like a plural when it is preceded by a number, as in "that man is six foot tall".

Historically, the "foot" was a part of many local systems of units, including the Greek, Roman, Chinese, French, and English systems. It varied in length from country to country, from city to city, and sometimes from trade to trade. Its length was usually between 250 mm (9.8 in) and 335 mm (13.2 in) and was generally, but not always, subdivided into twelve inches or 16 digits.

The cubit is an ancient unit of length based on the distance from the elbow to the tip of the middle finger. It was primarily associated with the Sumerians, Egyptians, and Israelites. The term cubit is found in the Bible regarding Noah's Ark, the Ark of the Covenant, the Tabernacle, and Solomon's Temple. The common cubit was divided into 6 palms × 4 fingers = 24 digits. Royal cubits added a palm for 7 palms × 4 fingers = 28 digits. These lengths typically ranged from 44.4 to 52.92 cm (1 ft 5+1⁄2 in to 1 ft 8+13⁄16 in), with an ancient Roman cubit being as long as 120 cm (3 ft 11 in).

Cubits of various lengths were employed in many parts of the world in antiquity, during the Middle Ages and as recently as early modern times. The term is still used in hedgelaying, the length of the forearm being frequently used to determine the interval between stakes placed within the hedge.

The palm is an obsolete anthropic unit of length, originally based on the width of the human palm and then variously standardized. The same name is also used for a second, rather larger unit based on the length of the human hand.

The width of the palm was a traditional unit in Ancient Egypt, Israel, Greece, and Rome and in medieval England, where it was also known as the hand, handbreadth, or handsbreadth.

A finger (sometimes fingerbreadth or finger's breadth) is any of several units of measurement that are approximately the width of an adult human finger. [Exactly which part of the finger should be used is not defined; the width at the base of fingernail (#6 in the sketch) is typically less than that at the knuckle (#5).]

The digit, also known as digitus or digitus transversus (Latin), dactyl (Greek) or dactylus, or finger's breadth – 3⁄4 of an inch or 1⁄16 of a foot. (about 2 cm)