According to the GAO, the US provided $31.1 million to the IPCC over the 10-year period from 2001-2010 - or $3,1 million/year.
http://www.gao.gov/products/GAO-12-43
As for Denier math skills - they are even worse than Denier language skills. In both cases, Deniers randomly generate strings of words or numbers to which they assign post hoc definitions - as needed.
Yahoo Answers is a question and answer website, supported by its' community members. It does not employ "mathematicians of Yahoo Answer Postmodern Climate Science." I honestly have to question the premise of your query.
Why would you compare Exxon to the IPCC? Two separate entities in function and purpose. Or if your into math: apples-vs- oranges.
$120,000,000 / $414,000,000,000 = 2.899e-4
2.899e-4 year * 365.25 day/year = 0.1059day * 24hr/day = ~ 2 and 1/2 hours
Re your additional details.
Oops! I forgot that I was supposed to use the new math. The new denialist math. Sorry.
According to the additional detail ("$300 million and $600 million over the 2008-12 period") that self-answers this "question" of Ottawa Mike ("Do you have any idea how many of your tax dollars go towards the UNFCCC? http://answers.yahoo.com/question/index;_ylt=AiRpKO.gUJndGcWabiKwRGvsy6IX;_ylv=3?qid=20130603124502AAX0Bqd), this funding of IPCC, using old-fashioned grade school arithmetic, would need $300-600 mil. per 5 years / 5 years = $60-120 per year.
According, again to old-fashioned honesty-not-challenged school math, $60 million per year would be (60/414,000=) .014% of $414 billion, which latter number is the annual revenues of Exxon-Mobil, according to http://finance.yahoo.com/q/ks?s=XOM+Key+Statistics
IPCC costing taxpayers .014-.028% (or 140-280 parts per million) as much per year as Exxon-Mobil collects in revenues, would mean (according to the aforementioned pre YA Cutting-Edge-Science math) that to operate IPCC for one YEAR costs about what Exxon collects in 80 to 160 MINUTES.
[ Hours per year = 1 / 365 / 24 = .011%,
thus, .014-.028% / .011% ≈ 1 1/3 to 2 2/3 hours = 80-160 minutes ]
But from the genius mathematicians of Yahoo Answer Postmodern Climate Science, we know that although increasing the cyanide solution in water from 280 ppm to 400 ppm would be just over a 40% increase, increasing CO2 in air from 280 to 400 ppm is only a 0.012% increase.
So how do we do the new YA Global Warming math here?
Ottawa, and his crew of New YA Climate Science geniuses here, have been "reading" peer-reviewed and Wattsup-or-equivalent-filtered climate science articles since about 2004 when Michael Crichton's definitive As-American-as-Hostess-Twinkies Climate Science text appeared:
http://en.wikipedia.org/wiki/State_of_Fear
http://www.realclimate.org/index.php/archives/2005/09/inhofe-and-crichton-together-at-last/
So now, under the New Post Crichtonian Climate Science Math of YA Global Warming, how long does it take Exxon-Mobil to generate in revenues ($414 billion per year) an amount necessary to fund the IPCC for a year ($60-120 million)?
