Even regionals will audit your logbook...they are mainly looking to see that you have all of your original endorsements and have maintained legal currency, and that there are no obvious signs of fraud.

But if there is a math error that you can find, they can find it too, and it won't reflect too well on you. Find the source of the error, and make a one-time correction on your current page, noting the date and nature of the error. But don't ignore it.