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Glite Dictionary
Napier's bones

Napier's bones

1 9.9
A set of numbered rods used before calculators to help multiply and divide numbers
  • noun
  • /ˈneɪpiərz boʊnz/
  • Archaic
: huesos de Napier
  • Before calculators, Napier's bones were popular among merchants for handling large multiplications.

Examples

  • The museum displayed an original set of Napier's bones next to other early calculating tools.

  • Teachers sometimes use replicas of Napier's bones to explain historical methods of arithmetic.

  • Have you ever seen Napier's bones in a museum?

  • I found a set of Napier's bones at an antique shop.

  • Before calculators became common, Napier's bones were used by merchants to make large multiplications easier.

  • In math class, students learned how to use Napier's bones as a historical tool for multiplication.

  • The exhibit included Napier's bones, showcasing how calculations were performed before modern technology.

Synonyms

Napier's rods
vsNapier's bones
  • Archaic
9.9

A set of numbered rods used to do multiplication and division by hand

has identical meaning but uses a different traditional name

Surface Forms

Napier's bones singular
Napier's bones plural

Morphology

Napier's + bones

This is an eponymous name (Napier's) combined with a common noun (bones) where the literal meanings do not indicate a calculation device; a B1 learner who knows the words would not be able to infer that it refers to a set of numbered rods for arithmetic. The meaning depends on historical/cultural knowledge of John Napier and the invention, making the expression unpredictable from its parts.

Etymology

Napier's bones comes from a tool John Napier made in the 1600s: a set of long numbered rods that looked like animal bones. People slid the rods and read the numbers to 'multiply' or 'divide', so the name now means a set of rods used to help calculation.