"The idea of extending the decimal place-value system to include fractions was discovered by several mathematicians. The most influential... was Simon Stevin... who popularized the system in a booklet called De Thiende (“The tenth”), first published in 1585. By extending place value to tenths, hundredths, and so on, Stevin created the system... More importantly, he explained how it simplified calculations... Stevin was aware that his system provided a way to attach a "number" (...decimal expansion) to every... length. ...In his Arithmetic he declared that... roots were just numbers. ...that "there are no absurd, irrational, irregular, inexplicable, or surd numbers" ...all terms for irrational numbers ...Stevin was proposing ...to flatten the incredible diversity of "quantities" or "magnitudes" into one expansive notion of number, defined by decimal expansions. ...this amounted to a fairly clear notion of... the positive real numbers. Stevin's proposal was made immensely more influential by the invention of logarithms. Like the sine and the cosine, these were practical computational tools. ...they needed to be tabulated, and the tables were given in decimal form. Very soon, everyone was using decimal representation. ...The positive real numbers are... an immensely larger number system, whose internal complexity we still do not fully understand."