An edition of The art of numbring by speaking-rods, vulgarly termed Nepeirs bones (1667)

The art of numbring by speaking-rods, vulgarly termed Nepeirs bones

by which the most difficult parts of arithmetick, as multiplication, division, and extracting of roots both square and cube, are performed with incredible celerity and exactness (without any charge to the memory) by addition and subtraction only

By William Leybourn