What's the difference between an English "Billion" and a French "Billion"?
Answer: 3 zeros.
Since the 1970s, the English language (both British and American) has assigned “1,000,000,000” (109 ) as being one billion. This is equivalent to the French’s “milliard.” On the other hand, what the French names as billion or also commonly known as “mille milliard”, is “1,000,000,000,000” (1012 – 12 zeros – which is English’s one trillion (yes, it’s confusing!).
The origins of the number system could be traced back to the 16th century. To cut the long story short, the British was using the French numbering system: “1,000,000,000” was called one “millard” while 1012 was one “billion”. This type of number is called the long scale system. It is still being used in several countries in Continental Europe and Latin America.
The other system is called the short scale system which has been adopted by many English-speaking and Arabic-speaking countries. The Americans switched to the short scale system in the beginning of the 19th century and the British in 1974.