there is nothing that is so troublesome to mathematical practice, nor
that doth more molest and hinder calculators, than the multiplications,
divisions, square and cubical extractions of great numbers ... I began
therefore to consider in my mind by what certain and ready art I might
remove those hindrances."
Mirifici logarithmorum canonis descriptio (Napier)
teaches (to speak in a word) the easy performance of all reckonings,
computations and accounts, without broken numbers [common fractions],
which can happen in man's business, in such a sort as that the four
principles of arithmetic, namely addition, subttraction, multiplication
and division, by whole numbers may satisfy these effects."
Introducing decimals in De Thiende (Stevinus)