Long and short number scales?
* https://en.wikipedia.org/wiki/Long_and_short_scales
Is "billion" a thousand million (10^9) or a million million (10^12)? Numberphile video:
* https://www.youtube.com/watch?v=C-52AI_ojyQ&t=5m30s
TL;DR: billion = bi-million = two of 10^6 = 10^{6x2} = 10^12. trillion = tri-million = 10^{6x3} = 10^18, and not 10^12. quadrillion, pent….