|Just as another idea, you can check if your Numbers are really numbers|
with the =ISNUMBER() function
Open up a new column next to your lookup values and add the formula:
If it returns TRUE then it's a number, otherswise it's Text
Also, in regards to the #N/A error message:
Excel VLOOKUP Error Messages
The following error messages are associated with VLOOKUP.
AN #N/A error is displayed if:
The lookup value is not found in the first column of the table array.
The range for the table array argument is inaccurate.
For example, the argument may include empty columns on the left side of the table array.
The range lookup argument is set to true and an exact match for the lookup_value argument cannot be found in the first column of the table array.