Problem: Mathematics: From the earliest the Chinese used a positional decimal system on counting boards in order to calculate. To express 10, a single rod is placed in the second box from the right. The spoken language uses a similar system to English: e.g. four thousand two hundred seven. No symbol was used for zero. By the 1st century BC, negative numbers and decimal fractions were in use and The Nine Chapters on the Mathematical Art included methods for extracting higher order roots by Horner's method and solving linear equations and by Pythagoras' theorem. Cubic equations were solved in the Tang dynasty and solutions of equations of order higher than 3 appeared in print in 1245 AD by Ch'in Chiu-shao. Pascal's triangle for binomial coefficients was described around 1100 by Jia Xian.
When did negative numbers and decimals start being used?
The answer is the following: 1st century BC

Problem: London i/lndn/ is the capital and most populous city of England and the United Kingdom. Standing on the River Thames in the south eastern part of the island of Great Britain, London has been a major settlement for two millennia. It was founded by the Romans, who named it Londinium. London's ancient core, the City of London, largely retains its 1.12-square-mile (2.9 km2) medieval boundaries and in 2011 had a resident population of 7,375, making it the smallest city in England. Since at least the 19th century, the term London has also referred to the metropolis developed around this core. The bulk of this conurbation forms Greater London,[note 1] a region of England governed by the Mayor of London and the London Assembly.[note 2] The conurbation also covers two English counties: the small district of the City of London and the county of Greater London. The latter constitutes the vast majority of London, though historically it was split between Middlesex (a now abolished county), Essex, Surrey, Kent and Hertfordshire.
Who founded the city of London?
The answer is the following: the Romans

Problem: In 1982, the band released the album Hot Space, a departure from their trademark seventies sound, this time being a mixture of rock, pop rock, dance, funk, and R&B. Most of the album was recorded in Munich during the most turbulent period in the band's history, and Taylor and May lamented the new sound, with both being very critical of the influence Mercury's personal manager Paul Prenter had on the singer. May was also scathing of Prenter, who was Mercury's manager from the early 1980s to 1984, for being dismissive of the importance of radio stations, such as the US networks, and their vital connection between the artist and the community, and for denying them access to Mercury. The band stopped touring North America after their Hot Space Tour, as their success there had waned, although they would perform on American television for the only time during the eighth season premiere of Saturday Night Live. Queen left Elektra Records, their label in the United States, Canada, Japan, Australia, and New Zealand, and signed onto EMI/Capitol Records.
Where did Queen record their 1982 album?
The answer is the following: Munich

Problem: With a population of 518,000, Hanover is a major centre of Northern Germany and the country's thirteenth largest city. Hanover also hosts annual commercial trade fairs such as the Hanover Fair and the CeBIT. Every year Hanover hosts the Schutzenfest Hannover, the world's largest marksmen's festival, and the Oktoberfest Hannover, the second largest Oktoberfest in the world (beside Oktoberfest of Blumenau). In 2000, Hanover hosted the world fair Expo 2000. The Hanover fairground, due to numerous extensions, especially for the Expo 2000, is the largest in the world. Hanover is of national importance because of its universities and medical school, its international airport and its large zoo. The city is also a major crossing point of railway lines and highways (Autobahnen), connecting European main lines in both the east-west (BerlinRuhr area) and north-south (HamburgMunich, etc.) directions.
What is Hanover's ranking in terms of size in Germany?
The answer is the following:
thirteenth largest