How much is one trillion?  I need a definition in terms of billions.

Dear 5krun01,

In the American system one billion is 1,000,000,000 and a trillion is
1,000,000,000,000 so one trillion is one thousand times one billion.

In the British system (and in entire Europe), one billion is
1,000,000,000,000 and one trillion is 1,000,000,000,000,000,000, so
one trillion is one million times one billion. The American billion
(1,000,000,000) is known as milliard.

Sources:

Walnut on the Web: How big is a billion dollars?
http://www.hybridwalnut.com/Billion.html

Math Central: How many billions equal one trillion?
http://mathcentral.uregina.ca/QQ/database/QQ.09.02/ryanandaylah1.html

Math Central: Billions and more!
http://mathcentral.uregina.ca/QQ/database/QQ.09.97/gupta1.html

Search terms used:
"trillion is one thousand"
://www.google.de/search?hl=de&ie=UTF-8&oe=UTF-8&newwindow=1&q=%22trillion+is+one+thousand%22&meta=

Hope this answers your question!
Best regards,
Scriptor

Thanks.  You came up with just what I wanted.

Dear 5krun01,

Scriptor is right when s/he says that the British billion and trillion
were different from the US ones, but the emphasis is on "were".  Many
years ago now, the UK Treasury (= finance ministry) started using
"billion" in monetary amounts with its US meaning.  Although
historians and purists may hold to the older usage, everyone in the UK
would these days understand "billion" to mean a thousand million. 
Just take a look at the first article on the business pages of today's
The [London] Times:

http://www.timesonline.co.uk/article/0,,5-598781,00.html

- the "£171bn hole" referred to will be 171 thousand million pounds
sterling, not a thousand times that.

In mathematical or scientific contexts, of course, either exponential
notation (10 to the power 9, 10 to the power 12) or standard
multipliers (giga-, tera-) are used, and no confusion arises.

I hope this helps.

Carnegie