What is half a billion?

Depending on the term billion (UK or US - Long vs short).

• US - 1,000,000,000 /2 = 500,000,000
• UK - 1,000,000,000 /2 = 500,000,000,000

In the US a billion is a thousand million whereas the UK and most of Europe the value is a million million. Why? Probably US millionaires wanted to be exclusive.

See related link.