The ROUND function rounds a number to a given number of places. The number of places is set by the number of digits provided in the second argument (num_digits). For example, the formulas below round the number 5.86 to 1 and zero places:
=ROUND(5.86,1) // returns 5.9 =ROUND(5.86,0) // returns 6
In the example shown, we are rounding the values in column B (which are created with the PI function) using the numbers in column B for digits. The formula in cell D6 is
This tells Excel to take the value in B6 (PI) and round it to the number of digits in cell C6 (4) with a result of 3.1416
In the table, the ROUND function is used to round the same number (PI) to a decreasing number of digits, starting at 4 and moving down past zero to -1. Notice that digits greater than zero round to the right of the decimal point, and digits less than or equal to zero round to the left.