James Bernard captured this sign after passing under it at least 50 times without recognizing the mathematical significance that it was hiding.

Mr. Bernard applied some very nice crunching to make this sign unwind.

This sign is on westbound highway 235 in Des Moines, Iowa. See sign on map!

It seems that this is a question of decimals, integers and units. My view is that we have three kinds of units associated with integers in this sign: 35, an integer with comes from the federal government and indicates a highway, let’s call this highway units; 88, an integer which indicates miles from some base point, let’s call this mile units; and 7, an integer which indicates tenths of a mile from some base point, let’s call this tenths of a mile units.

Indeed this sign escapes rule #3 by an incredibly thin margin. If the sign contained a “.7″ (which is more normal than the color differentiation), it clearly would not be allowed in Road Sign Math.

While the sign is very exciting, the math is yet another example of the most common pi calculation, 22 over 7.

{88 \over {35 – 7}} \equiv 3.142857 \equiv 3.14 \equiv \pi

This sign is found in Iowa on southbound I-35, a few miles north of Des Moines. The GPS coordinates are approximately N41 41 11.8 W93 34 33.2. See sign on map!

Dave Oosterhuis contributes this sign pair from Davenport, Iowa. It seems to be a fairly common practice for a math loving city to put multiple road signs on the freeways that show similar mathematical relationships (see Welcome To Omaha and Welcome to Albuquerque). Davenport joins in the fun but adds a little sprinkle of intrigue at the same time! See if you can find it.

These signs both take advantage of the somewhat controversial rule #4 that allows you to not use the numbers in the freeway designators because this is a mileage sign. This rule is currently under review and may change in the future.

Hard to miss the math on the right side. Basic, simple addition.

Same to be said for this sign, again, basic addition.

So did you see the intrigue? The sign on top indicates the distance from Northwest Blvd to Brady St as 2 miles, and the second sign shows it as 3 miles. It’s possible this is simply a mistake, or a bias in how rounding occurs to get to nice, round integers. However, it’s also possible that Iowa has perfected some sort of flux capacitor that makes the distance actually shorter one way. Alternatively, perhaps after thousands of years of eating spice Iowans are now able to bend roads, that is to go from Northwest Blvd to Brady St without moving.

These signs were found on I-80 north of Davenport, Iowa. The first sign is found eastbound and the second sign is found westbound. The GPS coordinates are approximately N41 36 12.9 W90 39 49.7. See sign on map!

Ed.: This is the 70th winner on Road Sign Math and ties Iowa for the 2nd position in the state competition with 7 signs each!

Dave Oosterhuis and his wife Phoebe continue their journey to Iowa City for homecoming weekend and along the way come across more mathematically significant roadsigns. This time they found math in the sign notifying them of the 137 households of Brandon, Iowa.

This sign has an unmistakeable similarity to Three Types, the very first sign ever posted on Road Sign Math.

This sign tries to obsure it’s mathematical relationship by putting numbers far away from each other, and even trying to hide one number inside the road indicator. Remember that because of rule #4 the “D48″ is used as 48.

This sign was found on I-380 southbound approaching exit 49. The GPS coordinates are approximately N42 19 31.5 W91 59 36.4. See sign on map!

This week on Road Sign Math continues to be brought to you by Dave Oosterhuis and his wife Phoebe. This sign brings us closer to their final destination as they cross into Iowa, as it points the way to a rather interesting set of cities. New Hampton sounds like a place where you could get lobster and blueberries, Riceville is obviously the home of Condoleezza Rice. Cresco really caught my eye though. There seems to be no connection to Crisco, but it does lay claim on being Iowa‘s Year ‘Round Playground!

This sign is elegant and understated in it’s mathematical connection. It also has a unique quality in the ordering. Typically road signs progress in shortest distance on top to longest distance on the bottom. Here, order was thrown to the window and chaos ruled.

This sign was found in Iowa on highway 63 southbound as it connects with highway 9, just south of Lime Springs. The GPS coordinates are approximated at N43 22 15.7 W92 17 54.0. See sign on map!

This winning sign takes us to Des Moines, Iowa and is the second submission from fellow enthusiast for mathematically significant road signs and Iowa native, Jim Bernard. This sign is best described in Jim’s own words.

Dear Road Sign Math,

Please find my respectful submission to your totally awesome game. I took this picture while driving to Des Moines. It is located just south of the I-35/I-80 split on I-235 that goes through Des Moines.

Des Moines is a great city. Did you know that the Des Moines metropolitan consists of parts of five counties, including Guthrie county? It was named by a guy named Theophilus Bryan (he was a Sheriff) in honor of his friend Captain Edwin B. Guthrie who was an officer of a company of Iowa volunteers in the Mexican war! He was most definately not killed by football players in Minnesota.

In another amazing Iowa-related Guthrie incident, the famous folk singer Woody Guthrie’s famous grandson Arlo called NPR in August of 2004 from the Flying J truck stop in Des Moines, Iowa. He was calling regarding the Internet sensation from Jib-Jab which used Woody’s anthem “This Land is Your Land.” I’ve eaten eggs at the Flying J. They were good.

Des Moines is run by a guy named Frank who looks like he might even be related to me. But then, all Iowan really do look similar, don’t you think?

In any case, hope you find room for my sign on your website!

Well Jim, for a sign like this, of course we can find room!

This sign is very deceptive, the math is hidden. Upon first look, the casual observer, or even the founder of Road Sign Math was not able to see the math immediately. The key to this sign is to realize that any number divided by itself is 1! We should also take note of this signs homage to Euclid, the father of Euclidean Geometry.

This sign was discovered in Iowa on Interstate 235 just after the I-35/I-80 junction in Des Moines, Iowa. The GPS coordinates are approximated at N41 38 31.3 W93 34 32.5. See sign on map!

Ed.: This is the fourth sign for Iowa placing it in a dead heat with Pennsylvania and Nebraska for the second most mathematical road signs behind the current leader New Mexico, which still has five signs.

This winning sign takes us to beautiful Ames, Iowa, where biotech comes to life. You may know Ames for the University, but it is also well known for housing the USDA Veterinary Labs (one of only two in the country). Ames is a city filled with history, including a nod to the first black college football player in Iowa, Jack Trice, who is paid homage in this sign and the stadium named after him as a victim of racial prejudice. This is the first sign from a huge fan of mathematically significant road signs and an Iowa native, Jim Bernard. (Messr. Bernard is also a member of the Blue Ribbon committee and as such will not be allowed to vote on this sign.)

This sign throws an entry-level curve ball at us with the 1, however math sign afficianados are quick to remember the identity property and excuse the 1 out-of-hand. You are left with a classic road sign pattern of

This sign was discovered in Iowa off of Interstate 35 at exit 111 heading into Ames, Iowa. The GPS coordinates are approximated at N42 00 44.7 W93 34 19.0. See sign on map!

Road Sign Math is a particularly difficult game to play with signs that have only two numbers (remember, by the rules in mileage signs you are not allowed to use any road numbers, only distance indicators). The lack of a third (or more) number requires you to use math functions that requires only a single number. This sign is one of the most simplistic of these.

The math is obvious…

\sqrt 4 = 2

This sign was discovered on a rainy day in Iowa on highway 18 westbound just before mile marker 182. The GPS coordinates are N 43 06.334 W 93 16.772. See sign on map!

The inaugural sign for Road Sign Math! This sign is interesting because it takes three numbers from three different sources. The exit number, the road number and the distance.

The math is very simple. (Remember the rules, in signs like this we can omit the “W“ on the road number 36!)

36 – 35 = 1

This sign was found off of Highway 280 in Iowa, Northbound past Cedar Rapids at exit (you guessed it) 35! It’s GPS coordinates are N 42 9.563 W 91 45.521. See sign on map!