Nearby, you will also find a direction written out (e.g., WEST). Note that the direction written closest to the two-digit number is the opposite direction where you'll want to go to find the final stage / cache (although if you look a bit more, you may find the true direction of the cache written a bit further away from the number, but also nearby).
Using the number you've found, subtract the first digit of the two (i.e. if the number were 15, you'd be subtracting 1) from the 2nd, 4th, & 6th N° coordinate numbers below, and also subtract the second digit number (again, if we use 15 as the example, then 5) from the 1st, 3rd, and 5th numbers of the W° coordinates to create the true coordinates.
Here are the coordinates you need to modify, which will lead you to your final destination (the underlined numbers are the ones that need to be changed; the rest are correct as is):
N 42° 03.589 W 616° 49.867
Hence if the number you were looking for were 15, then you'd subtract 1 from the 2nd, 4th and 6th N° coordinate numbers, and 5 from the 1st, 3rd and 5th W° coordinate numbers and end up with:
N 41° 02.579 W 111° 44.867
(FYI, 15 is not the number you're looking for, so the coordinates above are not correct, they are for example purposes only...sorry!)
Head to the correct coordinates, and look for an abandoned building. The cache is located around the side that faces away from the closest paved road.
Before you head over, check your coordinates on GeoChecker.com.