Napier's Bones (or Rods)

- Build your own paper calculator! [instructions]


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This is a black and white image of a set of Napier's bones abacus cards arranged vertically against a black background. The 10 numbers labeled on each card, from left to right, are "1 2 3 4 5 6 7 8 9 0". [source]

- NAPIER'S Bones, held in palm of hand. Consisting of ten rods plus two extras, representing squares and cubes [source]

- Mechanical version of Napier's Bones
[source]