Napier's bones
01
ネピアの骨, ネピアの棒
a set of numbered rods used for multiplication and division, invented by John Napier in the 17th century
例
The mathematician demonstrated how to use Napier's bones to perform rapid calculations.
数学者は、素早い計算を行うためにネイピアの骨の使い方を実演しました。



























