Depends on what numbers you're attempting to affect.
For chip values, there is a preference (on the Preferences tab) Use whole numbers for chip values that will turn off fractional chip values everywhere.
If you're attempting to display the prizes on the Tournament page as whole numbers, you can modify the <prizes> token, and add the attribute roundOff="true". If you're using the built-in layout, edit the Prizes cell (on the Layout tab), and change <prizes orient="horizontal"> to <prizes orient="horizontal" roundOff="true">. Make sure to do this for Odd Rounds and Even Rounds.