Kellog Interchange

Todd Southworth brings this huge sign assemblage from Pomona, California.



Mr. Southworth freely admits that he shot this photo and figured the math out later. This solution wasn't an epiphany while going down the road at 70 miles an hour. He noticed the 71 + 10 first, realizing that was 81 which is easily 9 via a square root. The rest came together nicely! Hats off for the use of the factorial! !  !     !

$$57 - 42 + \sqrt{71 + 10} = 4!$$

This sign is on on eastbound I-10 at the Kellog Interchange where I-10, CA 57 and CA 71 meet in Pomona, California.