Road Sign Math

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 [...]

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Samer Adra storms onto the scene with his first sign from California.

The math works out nicely via this solution.
64 \div 32 = \sqrt{\sqrt{16}}
Samer had originally submitted this sign as a sequence sign, however, we couldn’t justify it. The sequence would have been….
2^4, 2^5, 2^6
This sign is on on I-80 heading west from Reno to [...]

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Steven Francis recently discovered Road Sign Math and has been searching for valid signs since, and found this one to send in for his first winner. Mr. Francis is a math teacher, so buckle your seat belts fans, it’s going to get a little crazy.

Mr. Francis submits this formula as the winner for the [...]

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Todd Southworth goes a mile down the road from Absolute Pi and puts another very similar sign on the scoreboard.

Mr. Southworth applies similar math here.
4 \times \arctan ( \tan ( 210^\circ + 15^\circ) ) = \pi
This sign is eastbound CA-210 at the transition to I-15 in Rancho Cucamonga, California. See sign on map!

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Todd Southworth, after bringing the first series sign to the game, now brings the first constant sign to equal pi, exactly. This sign should satisfy those that have criticized us for allowing loose approximations for pi.

Mr. Southworth takes the tangent of an angle in degrees and then the inverse tangent of the result to [...]

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Todd Southworth, on only his 2nd sign, and the 173rd sign ever submitted to Road Sign Math brings us the very first series sign! The dozens of seekers of mathematically significant roadsigns have found numerous basic and advanced signs, and even a lot of constant signs, but this is our very first series sign. [...]

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Todd Southworth, a newcomer to Road Sign Math, found this mathematically significant road sign a number of times on his way home. However, until he visited this site he didn’t appreciate the wonderful math contained inside it.

A couple of factorials bring this set of numbers together in an elegant way.
20 \times (\sqrt{9})! = 5!
This [...]

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Roger Knowles brings another simple sign that we’ve all probably seen.

Same numbers as Carpool Math, but different solution.
9-7 = 5-3
This sign is found in California on Highway 237 east just before Highway 101. See sign on map!

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Roger Knowles brings this simple sign that we’ve all probably seen.

Very basic math.
9+3 = 5+7
This sign is found in California on I-85 South just after El Camino Real. See sign on map!

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Roger Knowles found this mathematically significant roadsign combination while driving around San Jose.

Here we see a return of the most popular pi approximation on Road Sign Math — 22 over 7.
{{880} \div {280}} \approx 3.141 \approx \pi
This sign is located on I-280 in California. See sign on map!

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