how many zeros are in a billion?

You should google it.

I think in most places of the world a billion has 9 zeros.

But 

in some places it has 12 zeros.  

This is one reason that large ( and tiny) numbers are better written in scientific notation. :)

Scientific notation can not be misinterpreted. (At least not once you understand it)

1,000,000,000. Nine zeros.

Wrong, 1,000,000,000 is a milliard, 1,000,000,000,000 is a billion.