In each step of the American system, you go up by a factor of 1000 each time. There is no discontinuity. The problem was that there were once two billions, the

In each step of the American system, you go up by a factor of 1000 each time. There is no discontinuity. 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.