The book of Genesis has ten major sections, each beginning with "These are the generations of ..." (toledoth in Hebrew). Before the first of these sections is the famous account of the creation in seven days (part of which featured in this morning's Bible readings).
But this seven-day creation account also features the number ten (and lots of other numbers); significantly, ten times we read, "And God said". (Ten words, perhaps.) And three of the ten major sections are actually no more than genealogies, acting as preludes to subsequent narrative sections. So the bulk of the book divides quite neatly into 10 - 3 = seven sections.
The seven days divide quite neatly into 3+3+1 days: three days of calling/separating, three days of blessing/filling, and one day of rest. And the seven sections in the bulk of the book divide quite neatly into 1+3+3 sections: one section in (and then out of) the garden, three sections of corruption, and three sections of calling/separating (of one person out of a larger family) and blessing/filling (of that one person and his descendants).
And the verse separating the seven days from the seven sections has a mirror (chiastic, [AB]CC[BA]) structure to it, as if the whole book is meant to hinge around this point (with the LORD God at the centre):
These are the generations
of the heavens and the earth when they were created,
in the day that the LORD God made the earth and the heavens
(Genesis 2:4, ESV).
Putting that all together:
Prologue: Creation in 3+3+1 days (1:1-2:3)
1. "The generations of the heavens and the earth" (2:4-4:26)
2. "The generations of Adam": genealogy (5:1-32) + corruption (6:1-8)
3. "The generations of Noah": narrative (6:9-9:19) + corruption (9:20-29)
4. "The generations of the sons of Noah": genealogy (10:1-32) + corruption (11:1-9)
5. "The generations of Shem" (11:10-26): genealogy + 6. "The generations of Terah" (11:27-25:11): narrative
7. "The generations of Ishmael" (25:12-18): genealogy + 8. "The generations of Isaac" (25:19-35:29): narrative
9. "The generations of Esau" (36:1-37:1): genealogy + 10. "The generations of Jacob" (37:2-50:26): narrative
All of this suggests that we should try to understand Genesis 1, primarily, as the first chapter of the book of Genesis. The book of Genesis has one message, and Genesis 1 is part of that. I've tried to summarise the message of Genesis 1 in this way: Our God created and rules all things by his powerful word and according to his wise plan, which hopefully emphasises some of the big themes running through the whole book.