Bemidbar 1-10 is sandwiched by mention of the various tribal princes and their standards, marking these chapters as one coherent unit with an overarching theme: the journey to and preparation for entry into Israel.
Articles
See סדר ותוכן בספר במדבר, by R. Aviyah HaCohen, for analysis of the structure of the book of Bemidbar as a whole. He divides the book into three sections a) Bemidbar 1-10: the structure of the camp and its travels b) Bemidbar 11-20: complaints of the nation c) Bemidbar 21-34: preparations for conquest and inheritance.
Watch Bemidbar: The Story of Two Generations, by Dr. Yael Ziegler, for discussion of an alternative structure of the book of Bemidbar1 and an in depth look at the first sub-unit, chapters 1-10, which portrays an obedient, trusting nation, marked by inner harmony.
For further discussion of the use of literary envelopes (also called "inclusios") and analysis of other structural devices found in Tanakh, with many examples, see Structural Devices.