=AND(ISNUMBER(A1),A1=MIN($A1:$F1))works too. Both formulas are identical with the exception of ($A1:$F1) versus (1:1). Please comment on the differing logic
$A1:$F1 will restrict cond format to columns A and F in all rows to which the cond format is applied, while 1:1 would apply to all columns in all rows to which the cond format is applied. If column F is the limit, the former should be used.
Aladin