Just down the road from Flashing Root, on highway 16, is another mathematically significant roadsign bringing the Coyote state, South Dakota, into Road Sign Math. Randy Weiss found this sign that pays an ode to the presidents and their dedication to mathematics in a way that the Office of Management and Budget never could.

The math in this sign is great. Simple, straightforward and stunningly obvious.

10 + 12 = 22

This sign is found US 16 heading eastbound as it joins US 385. The GPS coordinates are approximately N43 56 58.5 W103 30 46.7. See sign on map!

Ed.: South Dakota becomes the 16th state to be found in Road Sign Math. We are 1/3^rd of the way to every state in the country!