How to Teach the Floss Rule + FREE Word List and Chart

What Is the FLOSS Rule?

👉 The FLOSS rule is a spelling generalization that says when a one-syllable word with a short vowel ends in the letter F, L, S, or Z, the last letter is doubled.

Words like huff, bell, moss, and buzz are all examples of words following the FLOSS rule.

👉 Why is it called the FLOSS rule? The word FLOSS is a helpful mnemonic device that helps kids remember which letters are commonly doubled (F, L, S). It also serves as an example of a FLOSS word since the ending SS is doubled.

You may notice that the letter Z is not included in the word ‘floss.’ Some teachers teach this as a Floss+Z Rule (pronounced “flossy”), but only a handful of words include a double z at the end.

The floss rule is sometimes referred to as the 1-1-1 rule (one syllable, one short vowel, ends in one consonant sound.) If the consonant sound is s, l, f, or z, it is doubled.

It’s also important to note that this is different from the 1-1-1 Doubling Rule for spelling words with vowel suffixes. Floss words don’t need to be doubled before adding a vowel suffix. Why? Because they don’t end in one consonant.

Step 2: Explicitly teach the rule.

In our phonics notebooks, students title their page “FLOSS + Z,” then write the rule, and then write example words that follow this rule.

Then, they draw a picture of the class doing the floss dance together.

We pull out our multi-sensory sound boxes and map the word “FLOSS.” Double letters will go in one Elkonin box, because they only make one sound.

We practice this a bunch of times using with various FLOSS words from the word list below.

You can also pair a fun read-aloud book: The Very Help Floss Rule. It’s adorable and gives plenty of good examples of FLOSS words.

Step 3: Practice!

After a bit, be sure to throw in some other words that do not end in F, L, S, or Z to see if they can actually apply the rule.

Throughout the week, we practice reading and spelling FLOSS words so the concept becomes firm.

Some ideas include playing FLOSS Bingo, reading decodable sentences and decodable books, doing word chaining, and engaging in other games like phonics read and roll.

Important Note: There are other words that follow the FLOSS rule but are intentionally not included on this list.

👉 Words with -all (ball), -oll (roll), and -ull (pull) are not included because the vowel sounds change slightly, like in glued sounds. Choose the words you introduce to students carefully and be sure they only include pure short vowels.

For more words that cover ALL phonics skills (including nonsense words), check out our Ultimate Word Lists resource with over 3000 words organized by skill.