=ArrayFormula({"Test"; query(value(CTA!C2:C)*0.8)})
How would I exclude the rest of the 0's in empty cells?
try:
=ARRAYFORMULA({"Test"; IFERROR(1/(1/(VALUE(CTA!C2:C)*0.8)))})
or:
=ARRAYFORMULA({"Test"; QUERY(VALUE(CTA!C2:C)*0.8; "where Col1 <> 0"; )})