Decimals in a spreadsheet can either be great or an eyesore, depending on where the decimals appear. While it's a good idea to retain as many decimal places as possible to keep calculations accurate, displaying eight decimal places deep as the final result may cause confusion.
Google Sheets has a convenient Roundup function that controls how many decimal places are displayed and automatically cleans up the numbers.
Google Sheets ROUNDUP Function
The image below displays examples and gives explanations for several results returned by the Google Sheets ROUNDUP function for data in column A of the worksheet. The results, shown in column C, depend on the value of the count argument.
The ROUNDUP Function Syntax and Arguments
The function syntax is the layout of the function and includes the function name, brackets, and arguments.
The syntax for the ROUNDUP function is:
=ROUNDUP(number, count)
The arguments for the function are number and count.
Number
The number argument is required and is 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
The count argument is optional and is 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, 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. Here are some examples:
 If the value of the count argument is set to 1, the function removes all digits to the right of the decimal point and rounds the first digit to the left of the decimal point up to 10 (see example 3 in the image above).
 If the value of the count argument is set to 2, the function removes all digits to the right of the decimal point and rounds the first and second digits to the left of the decimal point up to 100 (see example 5 in the image above).
ROUNDUP Function Summary
The ROUNDUP function:
 Reduces a value by a specific number of decimal places or digits.
 Always rounds the rounding digit upward.
 Alters the value of the data in the cell. This is different than formatting options that change the number of decimal places displayed without 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 these numbers are decreased in value by the function, are said to be rounded up (see examples 4 and 5 in the image above).
Google Sheets ROUNDUP Function Step by Step Example
This tutorial uses 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 of rounding numbers on calculations, both the original number and the rounded number will be multiplied by 10 and the results compared.
Enter the Data
Enter the following data into the designated cells.
Cell  Data 
A1  242.24134 
B1  10 
Enter the ROUNDUP Function
Google Sheets does not use dialog boxes to enter the function arguments as can be found in Excel. Instead, it has an autosuggest box that appears when 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 display.

Type the equal sign ( = ) followed by 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, select the name to enter the function name and an open round bracket into cell A2.
Enter the Function 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 2 as the count argument to reduce the number of decimal places for the value in cell A1 from five to three.

Type a ) (the closing round bracket) to complete the function arguments.

Press Enter on the keyboard to complete the function.

The answer 242.25 appears in cell A2.

Select cell A2 to display the complete function =ROUNDUP(A1,2) in the formula bar above the worksheet.
Use 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 asterisk symbol is used for multiplication in Google Sheets.

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 appears in cell C1.

In cell B2, type the number 10.

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 formula.

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