My fifth grader came home from Community Park School in Princeton the other day with a math problem that went something like this:

GERALD + DONALD = ROBERT

The letters in each name represent a different number, from zero to nine. What numbers are represented by each letter so that the mathematical equation works out?

As my 11-year-old quickly pointed out, T has to be an even number because D+D is the same as D times 2 -- always even. And G plus D (and R by itself) have to be nine or less -- otherwise the answer would have an extra letter. This reasoning is similar to what you go through figuring out how to create a more or less coherent issue of a newspaper such as U.S. 1. But if you can't follow the little fifth grade math puzzle above, don't worry. The logic needed to put out this newspaper is not nearly so demanding.

For whatever reason -- maybe the need to write my own emergency contingency plans in case the terrorists strike and leave everything in place except me -- I have been trying to articulate exactly what I do in my role as editor of this humble journal. Last week I considered the elements of editing a single article. This week I am trying to describe the process by which a single issue gets put together.

Let's begin with the math. Every Friday morning ad sales people Diana Joseph-Riley and Martha Moore run a preliminary total of the number of column inches booked into the next week's paper, as tabulated by a data base designed to keep track of those ads. Kathleen McBride Sisack and I refer to another data base that tracks each issue, how many pages it was, and how many inches of ads it contained. From that we guess at the number of pages the issue should contain.

For the issue you hold in your hands, the initial guess was 56 pages. But then we realized we had a fairly substantial feature story we wanted to use as a cover story, and that we were already pushing the limit of how many ads would fit into a 56-page paper. So we increased it to 60.

Then Sisack and I conferred with Preview editor Nicole Plett. Her section goes together first and its size would determine the number of pages left for the rest of the paper. The choice is typically between 24, 28, and 32 (turn to page 17 of this issue and note how it is physically connected to page 44, the back cover, and you will realize why this section always comes out in four-page increments). For this issue, based on Plett's needs for her stories, we carved out the space for a 28-page Preview. That meant 32 pages were left for the front and the back, making page 16 (half of 32) the last page before the Preview, and page 45 the first page after the Preview.

So that's how it stood on Friday, and Plett forged ahead with her section, filling it with the day-by-day listings, and eight reviews and features, including two written by herself.

Then came the dark cloud of that slightly less than fifth grade logic. Just as a fifth grader might take a guess at the values for D and T in the problem above, and then two or three places later discover that they just don't work out, so we at U.S. 1 have to consider a mid-course correction in our layout. That 28-page section might work for Plett, but will the Survival Guide section edited by Kathleen McGinn Spring fit in its space? And what about the cover story and Life in the Fast Lane section edited by Barbara Fox? It has those pages in the back, minus the space taken up by the classified ads and this column.

Those sections also need the right amount of space; otherwise the balance of the paper is disrupted. Without the possibility of back tracking, the Survival Guide section in the front could end up running into the classified section in the back -- not good.

On many a woeful occasion, we have discovered that the guess on Friday didn't work on Monday. That often means that our Sunday guy (me) has to take apart some portion of what was all tied up on Friday (often his very own handiwork), and either make the entire paper bigger or smaller by four pages, or the Preview section bigger or smaller by four pages.

But this past Sunday the sun broke through. Survival Guide fit neatly in its space. Preview was good at 28 pages. The back half of the paper was a challenge. The cover story on Universal Display Corporation filled the paper up to page 50. But classifieds ran shorter than usual, and we needed something to fill pages 51 to 55. Barbara Fox had a story ready that would have quickly taken most of that space, but it also would have confronted readers with one more long story dealing with technological matters.

Instead Fox went back to the writing mode and got a dozen or so small stories into print. We expanded the Between the Lines section to print a backlog of letters, thereby tying page 2 of the paper to page 55. Everything fits, with no silly space fillers at the bottom of news columns. Now we can tear it all apart and start over. Perhaps the fifth graders can help.