It's also the British billion which is larger than the American billion.
(Unfortunately in my opinion: it seems more logical than the American/standard billion. We go up to nine until we run out of units and start on tens, until we run out at nine tens and nine and start on hundreds, until we run out at nine hundreds and nine tens and nine and start on thousands, until we run out at nine hundred and nine tens and nine thousand and nine hundreds and nine tens and nine and start on millions. Why then only go to nine hundred and nine tens and nine million (...)? It breaks the pattern of using all the expressable numbers until you run out and have to start a new word.)
The long scale makes sense because it is powers of a million -
- one million - 10^6,
- one billion (long scale) - 10^12 - ‘bi’ meaning two, is a million squared,
- one trillion (long scale) - 10^18 - ‘tri’ meaning three is a million cubed,
- one quadrillion (long scale) - 10^24 - ‘quad’ meaning four is a million to the power four.
The problem was that there were once two billions, the short billion and the long billion. The English world decided to use the short billion and the French world decided to use the long billion.