Numerical Prefixes: Mathematical, Digital, IEC

† 1,000,000,000 is called "one billion" in the U.S., U.K., France (before May 3, 1961), Brazil, Puerto Rico, Greece, and in Italy, Russia and Turkey it is referred to as "one billion" when written out, but as "one milliard" when written as 10⁹.    1,000,000,000,000 is called "one trillion" in the U.S., but is called "one billion" in Germany, the Netherlands, Austria, Sweden, Norway, Denmark, Finland, France (after May 3, 1961), Portugal, Poland.   It is best to check for current definitions for each country to be certain to get it right, or better yet, just write it out numerically to avoid confusion.