When someone makes an additional donation while registering for an event, there is no indication of the additional donation in the event record.  If you are on the participants tab, and you open a registrant record, there is no indicator an additional donation was made. Furthermore, on the Registration Fees tab, there are two sections which are misleading.

1) Amount paid: This amount ONLY includes the event registration amount, and not the additional donation.  So if I have someone who paid for two $40 tickets, then donated $20 to make their amount an even $100, the amount paid only reflects the $80, and ignores the additional $20.

2) Total Gift Amount: Same issue as above, ignores the additional donation.

To actually tell, from the registration fee tab you have to us the view gift button (one-click), then double click the gift to open the gift record (two-clicks), then you can finally realize the constituent made an additional donation. At this point you are 4 pages deep and it is easy to miss the fact that they made an additional donation.