It hasn't been deliberate, but most of the chapters I write end up being 7 pages. Some are longer, of course. And some shorter. But the average is 7.
Most weekend days, when I write, I write one chapter on Saturday and one chapter on Sunday. So, two chapters. Or about 14 pages.
Most books I write are between 300-350 pages. That's about 25 weekends' worth of writing, at about 14 pages apiece.
Some weekends, we have plans for one of the days. Rarely, we have plans for both days. But it's not unheard of - in a given month - that I won't be able to write at all for one weekend's worth of time.
So, if you assume writing three weekends a month, 25 weekends is a little over 8 months.
8 months to complete a book, 7 pages at a time.
What a remarkable thing!