What is the roman numeral for 3 billion?

Answer 1

That would depend on what you regard as a billion. A short-scale billion (predominantly American) is only 109 while a long scale billion (the rest of the world) is 1012. Under the long scale, 3,000,000,000 is just three thousand million, whereas 3,000,000,000,000 would be 3 trillion in the short scale.

Assuming the short-scale, 3,000,000,000 can't be notated using the accepted convention. You'd basically need 3,000,000 Ms. However, Middle-Age notation can be used to make it more manageable.

A combination of overlines and vertical bars multiplies the numeral by 100,000, however this still leaves us with 30,000, which is still too large to notate with anything other than 30 Ms.

However, Middle Age notation replaces the M with its original symbol CIƆ, which can be extended to cater for larger numbers, such that 10,000 is CCIƆƆ while CCIƆƆƆƆ is 15,000. Therefore we could extend this notation to its logical conclusion such that we have 1,500,000,000 + 1,500,000,000. That would still be quite cumbersome, but if we combine this notation with overlines and vertical bars, we'd reduce it to (15,000 + 15,000) x 100,000, which would be:

_________________

|CCIƆƆƆƆ CCIƆƆƆƆ|

A final modification would be to use condensed version of 10,000, which is ↂ, thus making:

___________

| ↂƆƆ ↂƆƆ |

While this may well be deemed acceptable (and logically correct), how many of us would actually recognise this as meaning a short scale 3 billion?

Answer 2

I M M