Pam,
it seems that you got your numbers from some import and there exist
non-printable characters in the cell. You will have to get rid of them
before you apply the VALUE() technique. First, you must understand the
pattern using text functions.
Use =LEN(F2), to see if the cell contains more characters than appear
at first. Most likely there will always be the same characters before
or after the number. If there always seem to be the same number of
invisible characters then you have to find if these numbers are placed
before or after the number. Use something like =MID(F2, 2, 1) to see
whether the 2nd character is the one you see.

Now, once you determine where the extra characters are and how many
they are, you can leave the number part only.
If the extra characters are before the number use =MID(F2, N+1,
LEN(F2)) to extract. If they are after the number use =LEFT(F2,
LEN(F2)-N), in both cases N is the number of extra characters. Use
VALUE() on the extracted portions.

Write back if (unlikely), you have variable number of extra characters.

HTH
Kostis Vezerides