It’s old news, but I just learned that in British English, through most of the twentieth century and before, numbers had different names from American English. I assumed that the prefix to a -llion number was always derived from (log10 n − 1) ÷ 3, or the number of thousands of thousands, but Brits used the simpler log10 n ÷ 6, or just the number of millions. A million is still a million in both systems, but, for example, an American septillion is a traditional British quadrillion, both of which equal 1024.
The American “short scale” has finally become the standard for English, but other countries and languages use the long scale.
We live in a world where it’s not even safe to spell numbers.