Step 1: Go to your "Prospects" header on the upper left-hand side of your account:

Step 2: Scroll all the way to the right where you will see a "+" button:

Step 3: Enter the new field that you want to for a number field and click "Save":https://cl.ly/2j3s2d451x3v

Step 4: Go into "Templates" at the top of the page:

Step 5: Click on either "New Template" or an existing template you're working out of:

Step 6: Enter the following command in the template:
#{{ yourCustomVariable | round }} but with the custom variable you just created inserted in "yourCustomVariable" for the filter to remove the .0 and leave you with rounded numbers: