How can I remove the #NUM from a cell and leave it blank?

I have 6 columns of numbers and in the 7th column I want the lowest number from the six and in the eight column I want the second lowest and in the 9th I want the sum of the 7th and 8th columns. I am using this formula for the second lowest number: =SMALL(IF(F3:K3<>0,F3:K3),$A$4)

The six columns do not all contain data yet. I only have data for the first two data entries right now. If there are 2 numbers it works fine. If there is text in the column it returns #NUM. I need this field to be left blank.

How can I fix this?

I cut and pasted the formula and it left the cell blank but when I carried the formula down for the rest of the column it blanks out my data