Stevin's Decimal Fraction Notation

Timeline

1. 1585Leiden · LeidenDe Thiende addressed astrologers, surveyors, carpet-measure assessors, and ordinary merchants; its title proclaimed that all everyday calculation could be done with integers. The definitions called integers the 'beginning' (Beghin, symbol ⓪), tenths the 'first' (①), and so on, extending place value downward. The four operations required only aligning the circled place numbers, with no need to write numerators and denominators. The French La Disme, translated by Stevin himself, appeared almost simultaneously with the Dutch text.
2. 1585–1590Leiden and Holland · HollandThe closing appendix advised: there was no need to abolish existing primary units of length, weight, or coin, but subdivisions should be tenths, hundredths, and thousandths, so that measurement, taxation, and military supply calculations matched decimal algorithms. This proposal anticipated the late-18th-century metric system, while already noting that notation reform must be tied to metrological reform. Stevin also defended Dutch scientific vocabulary, making the pamphlet a landmark text of practical mathematics in the United Provinces.
3. 1608–1619London and Edinburgh · British IslesIn 1608 Robert Norton translated De Thiende into English, giving surveyors and navigational calculators direct access to decimal algorithms. John Napier used a point or comma to separate integer and fractional parts in logarithmic calculation, making the circled place numbers seem cumbersome. Stevin's contribution thus shifted from a specific symbol to the principle that fractions must be expressed in decimal place value.
4. 1620European mathematical community · Western EuropeSeventeenth-century textbooks generally adopted the point or comma, and Stevin's circled symbols left everyday writing. His argument that 'a fraction is a place value extended downward' became common knowledge in modern arithmetic, while decimal currency and the metric system partially realized his appendix vision at a later date. Thus this object's symbolic form was clearly superseded, but its mathematical principle did not die.