rounding error

plural rounding errors

1. countableuncountablemathematicsThe difference between the result of a calculation using exact arithmetic and finite-precision, rounded arithmetic.

   The rocket's malfunction was down to a rounding error in the mathematics of its trajectory guidance.

   1 more example

   In an email, a computer program named Statcheck informed him that a 2013 paper he had published on multiculturalism and prejudice appeared to contain a number of incorrect calculations – which the program had catalogued and then posted on the internet for anyone to see. The problems turned out to be minor – just a few rounding errors – but the experience left Kauff feeling rattled.

   2017 February 1, Stephen Buranyi, “The high-tech war on science fraud”, in The Guardian

   Synonyms: roundoff error

2. broadlycountableuncountableA negligible fraction of something.

   In the budget of the rocket forces, the 200 thousand dollars for the investigation was a mere rounding error.

   3 more examples

   Microsoft's chief executive, Steve Ballmer, recently called Chrome's market share “a rounding error, to date” in an interview with TechCrunch.

   2009 September 30, Bobbie Johnson, quoting Steve Ballmer, “Does Google's Chrome Frame make your PC less secure?”, in The Guardian

   As Carl Emmerson, deputy head of the Institute for Fiscal Studies, said: “The size of the UK’s public finances means you can give away £1bn a year and it’s not much more than a rounding error.”

   2017 June 27, Phillip Inman, quoting Carl Emmerson, “Extra £1bn for Northern Ireland will barely dent public finances”, in The Guardian

   The sum of money involved is small and, compared to the trillions of dollars traded each year, almost a rounding error.

   2018 June 24, “There’s no panic yet: but Trump’s trade war could get out of hand”, in The Guardian