How to merge 6 fields into one field, but still return unique values?

Hi, I have 6 fields A B C D E F - Each have multiple unique numerical values.. I need to merge these unique numerical values into one new field.. basically to make it seem as if the 6 fields don't exist and only the one field containing all the numerical values the six fields have individually.. I then want to display the top 10 values of this newly created single field. Any thoughts? Thanks!