Letter Equations are well known phrases or facts where the key words have been replaced with the first letter of that word. These are often in the form of an equation, which contain a number, an = sign and the rest of the obscured phrase or fact.
3 = S in the F V of C C (N, P, S M)
3 = Ships in the First Voyage of Christopher Columbus (Nina, Pinta, Santa Maria)
Today's brain teaser courtesy of Braingle.com.