"This was [the result] for the descendants of Reuben, Israel's firstborn."
All of the tribes are recounted in this manner: for the tribe of Shimon..., for the tribe of Gad, but the last tribe of Naftali is special, and it is counted without the word “for,” that is, “the tribe of Naftali...”
This letter (lamed) in the Torah tells us what algorithm they used for counting. First they went through every tent and wrote down “so-and-so, son of so-and-so.” In taking this first raw count, they did not divide the people into tribes. It was a complete, unsorted count.
Then they went through the same book again, twelve times, one time for each tribe. Thus, they were counting “this man goes for the tribe of Shimon.” Then they would mark off his name on the margin of the list, to indicate that he was already counted.
When they came to the last tribe, there was no need to direct the scribe to which tribe the men belonged, because they all belonged to the last tribe, the tribe of Naftali.
We see that when dealing with one's name, it is proper to concentrate only on this name. When dealing with one tribe, it is proper to count members of only that one tribe. Each individual's name is of utmost importance, to the exclusion of everything else, since the name is the essence of this person, and each person can claim “for me the world was created.” The same is true for a group, like a tribe, and each has its own unique importance.
Art: Lambert de Hondt - The Creation