Teaching the FLOSS Spelling Rule Teaching the FLoSS spelling rule can be easy! Memory aids are often used to help students remember certain spelling rules. The FLoSS rule is one of the first spelling rules taught to our first and second grade students to help them understand when to double the final “f”, “l” and “s” consonants at the end of certain words.   The word “floss” actually follows the FLoSS rule.  When a /f/, /l/ /s/ (or /z/) is heard after a short vowel at the end of a one-syllable word, it is spelled with a double “ff”, “ll”, “ss” or “zz”.  Okay, you’re probably thinking how did that “z” sneak in there.  Well, there really aren’t too many words that end