GAWR + GAWR = GVWR ?

[DocB]

I recently had some issues re-titling and registering my truck and decided to take a look on the door jamb sticker for the manufacturers weight rating of the vehicle. I had no trouble increasing the registered weight to 10K. In NJ, the appropriate weight class is defined as 9-10K. Truck is in sig.
The following is on the sticker:

Front axle GAWR = 5200#
Rear axle GAWR = 6830#

GVWR = 9900#

What I don't understand is the math. This is not how I was taught to do arithmetic when I was in school. Can someone shed some light on this?

[44magnum]

Supposedly it has something to do with weight distribution, but I don't fully understand it either. They want you to be able to load it to the max GVWR and not go over either GAWR. But your front GAWR and rear GAWR will almost always be higher than the GVWR. The GVWR also depends on the frame, springs, brakes, etc etc. Just think of it as putting heavier axles under it than needed. Hopefully someone with more knowledge will chime in.