The flow rate increases 100-fold (one hundred-fold) Would be a more idiomatic way of saying this, however, the questioner asks specifically about the original phrasing. The above Ngram search would suggest that a one hundred has always been less frequently used in written language and as such should probably be avoided. Your other suggestion of by one hundred times is definitely better than a ...
As you note, "percent" means "for every hundred," so there is nothing at all wrong with percent values greater than 100 when discussing proportions, e.g. profits increased by 120%. Like fractions, however, percent values are longer to express than multiples, so for values much greater than 100 you may hear them less frequently:
relating to 100 years : marking or beginning a century, with the example "the centurial years 1600 and 1700". But there is a word that is widely used to indicate the range of years or centuries covered by an article or book: history.
Hypernym for numbers like 10, 100, 1,000, and so on Ask Question Asked 8 years, 2 months ago Modified 8 years, 2 months ago
To my ear, 'one hundred percent' sounds more emphatic than 'a hundred percent', simply because the former feels more deliberately phrased—conveying precisely 100% as opposed to about 100%.
One of the most confusing things for me is spelling English numerals. What is grammatical way to spell the following numbers in the context of writing the numeral in a receipt? $100 — a hu...
If I put "100% correct pronunciation" in the following sentence, is it understandable and correct? "100%" is what I would like to emphasize. If it is not right, how should it be