How Do You Spell Cow in 13 Letters?

Spell the names of the letters

Cow is spelled C, O, W. The riddle asks for those three letters to be written out by name: "see", "oh", "double you". Count the letters. SEE has three, the letter O is a single O, and DOUBLEYOU has nine. Three plus one plus nine makes thirteen.

The single O matters. Spelling the letter's name "oh" would make fourteen. The W matters too: written "double u" it takes seven letters instead of nine, and the total drops to eleven.

Why W is called double U

In English the letter W is named for how it was first written, as two U letters side by side. In older writing U and V were used for the same sounds, which is why the letter looks like two Vs but carries a name with a U. Some other languages kept the V: French says "double vé".

Counting without losing track

Write each name on its own and count it first. Then add the three numbers. It is a riddle that listeners tend to check on paper, which is part of its pull.