In this case, I'd use a formula variable. I chose to name the variable numOfDays, but you can use whatever name you want.
var text numOfDays = ToText(Round(([3. Close Duration]+[3. Finish Duration]+[3. Rough Duration]+[3. Sub Duration])/8, 0.01))& " " & "Days";
If($numOfDays != "0", $numOfDays & " " & "Days", " ")
If that doesn't work, try it this way. Depending on how you set up your fields, an empty result will either show up as 0 or " ":
If($numOfDays != " ", $numOfDays & " " & "Days", " ")
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Ahuva Brown
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