Decimals in your spreadsheets can either be great or an eyesore, depending on where they appear. While it's a good idea to retain as many decimal places as possible to keep your calculations accurate, you may not want to display a number eight decimal places deep as the final result.
Google Sheets has a convenient Roundup function that lets you control how many decimal places it displays and automatically clean up your numbers.
Google Spreadsheets' ROUNDUP Function
The image to below displays examples and gives explanations for a number of results returned by Google Spreadsheets' ROUNDUP function for data in column A of the worksheet. The results, shown in column C, depend upon the value of the count argument  more information below.
The ROUNDUP Function's Syntax and Arguments
A function's syntax refers to the layout of the function and includes the function's name, brackets, and arguments.
The syntax for the ROUNDUP function is:
= ROUNDUP ( number, count )
The arguments for the function are:
number  (required) the value to be rounded
 This argument can contain the actual data for rounding or it can be a cell reference to the location of the data in the worksheet.
count  (optional) the number of decimal places to leave
 if the count argument is omitted, the function rounds the value up to the nearest integer
 if the count argument is set to 1, for example, the function leaves only one digit to the right of the decimal point and rounds it up to the next number
 if the count argument is negative, all decimal places are removed and the function rounds up that number of digits to the left of the decimal point upward
 for example, if the value of the count argument is set to 1, the function will remove all digits to the right of the decimal point and round the first digit to the left of the decimal point up to 10  example 3 in the image above
 if the value of the count argument is set to 2, the function will remove all digits to the right of the decimal point and round the first and second digits to the left of the decimal point up to 100  example 5 in the image above
ROUNDUP Function Summary
The ROUNDUP Function:
 is used to reduce a value by a specific number of decimal places or digits;
 will always round the rounding digit upward;
 alters the value of the data in the cell  unlike formatting options that allow you to change the number of decimal places displayed without actually changing the value in the cell;
 affects the results of calculations due to this change in data.
 always rounds away from zero. Negative numbers, even though they are decreased in value by the function, are said to be rounded up (examples 4 and 5 in the image above).
Google Spreadsheets' ROUNDUP Function Step by Step Example
Example: Using the ROUNDUP Function in Google Spreadsheets
As seen in the image above, this example will use the ROUNDUP function to reduce the number in cell A1 to two decimal places. In addition, it will increase the value of the rounding digit by one.
To show the effect rounding numbers has on calculations, both the original number and the rounded one will then be multiplied by 10 and the results compared.
Entering the Data
Enter the following data into the designated cells.
Cell Data
A1  242.24134
B1  10
Entering the ROUNDUP Function
Google Spreadsheets does not use dialog boxes to enter a function's arguments as can be found in Excel. Instead, it has an autosuggest box that pops up as the name of the function is typed into a cell.

Select cell A2 to make it the active cell  this is where the results of the ROUNDUP function will be displayed.

Type the equal sign ( = ) followed by the name of the function ROUNDUP.

As you type, the autosuggest box appears with the names of functions that begin with the letter R.

When the name ROUNDUP appears in the box, click on the name with the mouse pointer to enter the function name and open round bracket into cell A2.
Entering the Function's Arguments

With the cursor located after the open round bracket, select cell A1 in the worksheet to enter that cell reference into the function as the Number argument.

Following the cell reference, type a comma ( , ) to act as a separator between the arguments.

After the comma type a one "2" as the count argument to reduce the number of decimal places for the value in A1 from five to three.

Type a closing round bracket " ) " to complete the function's arguments.

Press Enter on the keyboard to complete the function.

The answer 242.25 should appear in cell A2.

When you select cell A2 the complete function = ROUNDUP( A1 , 2 ) appears in the formula bar above the worksheet.
Using the Rounded Number in Calculations
In the image above, the value in cell C1 has been formatted to display only three digits to make the number easier to read.

Select cell C1 to make it the active cell  this is where the multiplication formula will be entered.

Type an equal sign to begin the formula.

Select cell A1 to enter that cell reference into the formula.

Type an asterisk ( * )  the symbol for multiplication in Google Spreadsheets.

Select cell B1 to enter that cell reference into the formula.

Press Enter on the keyboard to complete the formula.

The answer 2,422.413 should appear in cell C1.

Type the number 10 in cell B2.

Select cell C1 to make it the active cell.

Copy the formula in C1 to cell C2 using the Fill Handle or Copy and Paste.

The answer 2,422.50 should appear in cell C2.
The different formula results in cells C1 and C2  2,422.413 vs. 2,422.50 shows the effect rounding numbers can have on calculations, which can be a significant amount in certain circumstances.