=IF(AND($K$4>=1,$K$4<=4),"+2",IF(AND($K$4>="5",$K$4<="8"),"+3",IF(AND($K$4>="9",$K$4<="12"),"+4",IF(AND($K$4>=13,$K$4<=16),"+5",IF(AND($K$4>="Lvl 17",$K$4<="Lvl 20"),"+6")))))

I have that function, It was showing FALSE but when I put the "" around the numbers it worked except IF(AND($K$4>="9",$K$4<="12") Can anyone explain why this one portion is showing false? Is it because it goes from single digit to double? If so, how do I fix that?