It is not clear whether the question is about arithmetic, or about a practical method to
be used in construction. I think it is about arithmetic, in which case Peejay's answer is
exactly right. But I will answer it as a woodworker too, as this also contains mathematical
ideas. Don't measure anything. Use "dividers" (the tool by that name) if you have them,
otherwise take a scrap of paper and mark two points at the edge which you guess might be
near the right spacing. Them move the paper along the wood, lightly marking the tentative
positions, and of course you will come out too far to the left or right for hook number 6.
Then put new marks on your paper using your best guess again a little more or less than
before, and repeat. The result: pretty soon you will hit it near enough.
Mathematically what you have done is to create a convergent sequence of marks on your paper,
which might be either a monotone sequence if you are very cautious, or requires the squeeze
theorem if you are a little more aggressive in your adjustments.