First off, go through and total up each page until you find all the errors.

If you catch an error on a page before it gets carried forward to the next page you can line-out or white-out to correct the error. After the error get's carried forward, just use the next blank line in your logbook to make an entry (with today's date) to correct the totals. Enter a negative number if required, and in the comments explain what the correction was for and the date of the error.

This way you don't have to go back and change the totals on every page.