Use an electronic logbook, or spreadsheet, to figure out the correct totals. Make a correction entry in the next line in your logbook so that the totals at the bottom of your current page will be correct. It would look something like this:

"11/27/14", "Correction entry to fix addition errors on pages ending on 1/15/12, 8/5/14, and 10/5/14"

Enter a positive, or negative, number on that line so that the totals at the end of that page will be correct.

Going forward, use your electronic logbook or spreadsheet to verify the totals before entering them on each page.