Rounding to nearest integer symbol in Latex

The mathtools package has a \DeclarePairedDelimiter command which lets you define such macros. I defined a \nint command which encloses its argument between \lfloor and \rceil. The starred version adds a pair of implicit \left...\right, but you may fine-tune the delimiters size using one of \big, \Big, \bigg, \Biggas an optional argument.

\usepackage{mathtools, nccmath}




    \[ \nint{x}\qquad \nint*{\sqrt{x^2 + \mfrac13}}\qquad\nint[\Big]{\sqrt{x^2}} = \abs{x}\]%


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