Editing Slide calculator (section)

== History ==
{{refimprove|section|date=October 2023}}
Sometime between 1666 and 1675, French polymath [[Claude Perrault]] invented the first slide calculator, called ''Abaque rhabdologique'' (a [[Rabdology|rabdological]] [[abacus]]), when he needed to do a lot of calculations while working as an [[architect]].

About three decades later, around 1700 or shortly after, French businessman and amateur mathematician César Caze simplified Perrault's design and adapted it to counting money, getting a privilege (patent) in 1711. However, neither of these devices implemented a carry mechanism.

In 1845, German musician and amateur mechanic Heinrich Kummer, who was living in St. Petersburg, saw a mechanical calculator of a different design made by [[Hayyim Selig Slonimski]], and in the next year borrowed the idea of its carry mechanism to greatly improve Caze's device, leading to the modern variant of the slide calculator.

===Addiator===
In 1889, Louis-Joseph Troncet successfully commercialized the Addiator,<ref>{{cite news |url=https://www.newspapers.com/article/the-berkshire-eagle-vintage-calculator-c/136988519/ |title=Vintage calculator called an 'addiator' |first=Glenn |last=Erardi |newspaper=[[The Berkshire Eagle]] |location=[[Pittsfield, Massachusetts]] |page=E3 |date=May 3, 2003 |accessdate=December 17, 2023 |via=newspapers.com}}</ref> which became one of the most popular calculators of its kind, and the name is often used to refer to the type generally.
<ref>{{cite news |last1=Anton |first1=Mike |title=Calculator |url=https://ccalculators.co.uk |access-date=28 September 2021}}</ref>
Addiators appeared in newspaper advertisements as early as 1921, listed at a price of {{GBP|4|1921}} in the ''[[Daily Record (Scotland)|Daily Record]]'' of Scotland.<ref>{{cite news |url=https://www.newspapers.com/article/daily-record-addiator-pocket/136987207/ |title=Addiator Pocket |newspaper=[[Daily Record (Scotland)|Daily Record]] |location=[[Glasgow]] |page=19 |date=November 18, 1921 |accessdate=December 17, 2023 |via=newspapers.com}}</ref> As of 1968, Addiators were advertised in American newspapers starting at $3.98 each {{USDCY|3.98|1968}}.<ref>{{cite news |url=https://www.newspapers.com/article/danville-register-and-bee-does-1001-jobs/136986645/ |title=Does 1001 Jobs $150 Electrics Won't For 1/25 the Cost |newspaper=[[Danville Register & Bee]] |location=[[Danville, Virginia]] |page=Family Weekly pg. 7 |date=July 7, 1968 |accessdate=December 17, 2023 |via=newspapers.com}}</ref>