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Symbol | Definition |
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≡ | exactly equal |
≈ | approximately equal to |
= | equal to |
digits | indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …) |
A nail, as a unit of cloth measurement, is generally a sixteenth of a yard or 2 1/4 inches (5.715 cm). The nail was apparently named after the practice of hammering brass nails into the counter at shops where cloth was sold.
A pace is a unit of length consisting either of one normal walking step (~0.75 m), or of a double step, returning to the same foot (~1.5 m). Like other traditional measurements, paces started as informal units but have since been standardized, often with the specific length set according to a typical brisk or military marching stride.