Rounding is the approximation of a number by truncating and possibly adjusting the last digit of interest based on digits appearing after it.

The process of approximating a quantity, be it for convenience or, as in the case of numerical computations, of necessity. If rounding is performed on each of a series of numbers in a long computation, roundoff error can become important, especially if division by a small number ever occurs.

nearest integer function | round number | roundoff error | shadowing theorem

elementary school level (California grade 3 standard)