To round numbers, you can either change the way Excel displays decimal places, or you can use a set of function to change the actual number.
You can use functions to round numbers up, down, to the nearest even number, or to the nearest odd number. You can also round numbers to the nearest fraction, the nearest multiple, or the nearest significant digit.
Important: When you round a number by using a function, you're not just changing the formatting of the number; the underlying value in the cell is changed.
Do any of the following:
Change the number of decimal places displayed, without changing the number

Select the cells that you want to format.

On the Home tab, under Number, click Increase Decimal or Decrease Decimal .
The actual value of the cells that are stored in Excel does not change.
Round a number
Excel provides many different functions for rounding a number, depending on whether you are rounding up, rounding down, or rounding a number to a multiple of another number.
When you open the Formula Builder in Excel, instead of looking for your formula in a huge list, start to type the formula name into the search box. Within a few letters, the formula name you need will appear for you to doubleclick. Type the number that you are rounding directly into the number box in the Formula Builder.

Click in an empty cell.

On the Formulas tab, under Function, click Formula Builder.

Do any of the following:
To 
In the Formula Builder, search for, and then doubleclick 
Under Arguments 
Round a number up 
ROUNDUP 
In number, type the number you are rounding up. In num_digits, type 0 to round the number up to the nearest whole number. 
Round a number down 
ROUNDDOWN 
In number, type the number you are rounding down. In num_digits, type 0 to round the number up to the nearest whole number. 
Round up to an even number 
EVEN 
In number, type the number you are rounding. 
Round up to an odd number 
ODD 
In number, type the number you are rounding. 
Round a number to the nearest multiple of another number 
MROUND 
Click the box next to multiple, and then type the number you want the nearest multiple of. 

Press RETURN .
Round a number to a significant digit
Rounding to a number of significant figures is a generalpurpose technique for rounding, as it provides a consistent measure of precision to the numbers you are using.
When using an Excel rounding function, start by counting the number of digits in your original number (for example, 549282 has six digits). If your final number should have, for example, three significant digits, you would subtract the original number of digits from the desired number of digits. The result is the parameter to use in the ROUND, ROUNDUP, and ROUNDDOWN functions.

Count the number of digits in your original number.
For example, the value 549282 has six digits.

Determine the number of digits that the final number should have.
In this example, the final number should have three significant digits.

Subtract the total number of digits from the final number of significant digits to get the num_digit parameter.
In this example, we have 3 significant digits minus 6 total digits. So the num_digit parameter would be 3.

On the Formulas tab, under Function, click Formula Builder.

Use these parameters to create your function:
If the value in cell A1 is 
To 
Use 
549282 
Round to four significant digits 549300 
4 in the function =ROUND(A1,3) 
549282 
Round down to four significant digits 549200 
4 in the function =ROUNDDOWN(A1,4) 
549282 
Round up to two significant digits 550000 
4 in the function =ROUNDUP(A1,4) 
549282 
Round up to four significant digits 549300 
2 in the function =ROUNDUP(A1,2) 
549282 
Round down to four significant digits 549200 
2 in the function =ROUNDDOWN(A1,2) 
Notes:


Rounding a negative number down actually rounds it upward. When rounding a negative number, that number is first converted to its absolute value (its value without the negative sign). The rounding operation then occurs, and then the negative sign is reapplied. Although this may seem to defy logic, it is the way rounding works. For example, using the ROUNDDOWN function to round 889 to two significant digits gives a result of 880. First, 889 is converted to its absolute value of 889. Next, it is rounded down to two significant digits for a result of (880). Finally, the negative sign is reapplied, for a result of 880.

The ROUND function rounds a number that contains a fraction as follows: If the fractional part is 0.5 or greater, the number is rounded up. If the fractional part is less than 0.5, the number is rounded down. It rounds whole numbers up or down by following a similar rule; substituting multiples of 5 for 0.5.
