2012 Cachemas in STL Day 13 Mystery Cache

The cache is NOT located at the posted coordinates

In order to find this cache you must find all twelve 2012 Cachemas caches and use the numbers written on the caches to solve the math problem.

The cache will be at N38 30.ABC W090 36.DEF

To get ABC add the numbers on day 1-6 then subtract 5 and then divide 6 from that.

To get DEF add day 7-12 then add 2 and multiply 7 then add 3 from that.

Cachemas 2012 is here. There will be 13 caches placed starting on Dec 14th with a cache being place everyday until Cachemas Dec 25th. If you are able to FTF one of the caches there will be an FTF Cachemas ornament in the cache for you. PLEASE, if you get an FTF on one of the caches do not go for another FTF in the series. Let someone else have some fun.

There will be a thirteenth cachemas puzzle cache that can only be found using the numbers you find in all twelve Cachemas caches.