One can't just divide the number of labeled page sides (337) by two to get the number of sheets of paper because of oddities in the numbering. At least four times, blank sides were not numbered, switching first sides of sheets to even numbers instead of odd numbers (and vice versa). This is evident from knowing how the booklets are numbered: the entire booklet, regardless of size, has only one number. Further, because a booklet can only appear after a sheet, a booklet cannot appear between two page numbers from the same sheet of paper. A booklet can only appear after a sheet. When a booklet starts with, say, an even number, when (as far as one knew) new sheets had been starting with odd numbers, one knows that a page side wasn't numbered in the interim. Unnumbered blank pages possibly happened more than just the four times that the booklet numberings reveal.
Say at least one blank page side was skipped in the numbering, making a new sheets and booklets start with an even number, such as the case of the page 86 booklet. Then you know there must have been an unnumbered blank page side before then. The sheet after that "86" booklet is assumed to be pages 87 and 88. That is, we know that new sheets start with odd numbers again. Then, if a later blank page side was not labeled, subsequent numbering would again be even on the next new sheet's or booklet's first side. (One can't look to photos for help in knowing when this happens: the labeling of the loose sheets' pages is in the lower left corner of every page.) The intervening pages have unknown quantities of unnumbered blank pages. One would never know about any skip unless there were an odd, not even, number of them. Even with an even/odd discrepancy, one can't know just how many blank page sides were unnumbered since the last booklet. It must be greater than none, but it could be one time, or three times, or five times, etc. One only knows it was an odd number.

There are four sections that have at least one unnumbered blank page side. They are:

• between page 1 (first page of first sheet) and page 86 (booklet start);
• between page 87 (sheet start after booklet numbered 86) and page 128 (booklet start);
• page 129 (new sheet after even numbered booklet) and page 152 (booklet start);
• page 153 (new sheet after even numbered booklet) and page 280 (missing sheet is numbered 280 and 281, an even start -- only a photocopy exists, read CI, page 159.).

Conversely there is one numbered blank page: page 91.

Also, Otto Frank held back 5 pages (see the missing pages). Not being numbered, these pages also are not shown in the illustration. I don't know enough about these pages to feel comfortable adding them somewhere in the illustration. (Similarly, the tales and essays Anne had on unnumbered sheets of loose paper do not appear.)
One can't take the number on the final page side (324) and divide it by two to get the number of sheets not only because of the issues mentioned above, but also because of other page numbering oddities. Four sheets of paper were folded (height folded in half and written in booklets -- each booklet had four labeled page sides for each sheet of paper making up the booklet). The page sides of each of the three booklets were numbered with one number, but distinguished with letters for each additional page side within. (Specifically: The first booklet was made from two sheets of paper, forming 8 page sides. They were all given one number: 86. They were labeled 86 and 86a through 86g. The second booklet was made of one sheet, numbered 128 and 128a through 128c. The third was labeled 152 and 152a through 152c.) This means that 16 page sides got three numbers. 324 plus the 13 page sides labeled with letters in the booklets makes 337 labeled page sides.
Again, due to blank page sides not always being labeled, one can't just calculate to know for sure the number of sheets of paper. But one can calculate the minimum: take the number of labeled full page sides divided by two (remember that three of the 324 numbers were for booklets, not full page sides), plus the four sheets making up the booklets, plus two sheets' worth of known, unnumbered, blank page sides, (324-3)/2 + 4 + 2 = 166.5 sheets. Of course, round that up to get a whole number of sheets and one arrives at the minimum of 167 sheets, which is the number of sheets I show in the illustration.
The illustration shows 167 sheets of paper, the minimum possible. No point in cluttering it with more. The four unnumbered blank page sides (again using a minimum) are shown as half black and half gray. Page 91, the numbered blank page side, is shown as not quite half gray because it is numbered. Unlike page 91, not knowing exactly where the unnumbered blank pages lie, the illustration shows them in the middle of the sections that evidence an even/odd switch (as described earlier). The illustration is mostly for conceptual purposes, anyway.

  6 February 2002