To add to the complexity of the whole situation, some countries don't separate by thousands (every three zeroes). India uses a 2,2,3 system (crore, lakh, thousand).
Petrol stations... I have no idea how widespread this practice is, but at least in Germany fuel prices have 3 decimal points to better confuse motorists. The third number is usually displayed smaller and is of course always a nine. So, if you see the price for a litre of diesel at e.g. 1.62⁹ €, you might forget to round it up mentally.
10 million = 1,00,00,000
https://en.wikipedia.org/wiki/Lakh