Select the cell and then use the menu Format -> Cells to set the number of decimal places on the Numbers tab.
OpenOffice 4.1 on Windows 10 and Linux Mint
If your question is answered, please go to your first post, select the Edit button, and add [Solved] to the beginning of the title.
FJCC's suggestion changes the display, but not the actual number.
If you want the actual number changed, wrap the last term of your IF in an INT function.
OpenOffice 4.1.7, LibreOffice 7.0.1.2 on Windows 7 Pro, Ultimate & Windows 10 Home (2004)
If you believe your problem has been resolved, please go to your first post in this topic, click the Edit button and add [Solved] to the beginning of the Subject line.