Positive cell values displaying as negative

I have a column of numbers I'm adding up. I'm inserting new rows as payments are made. For the most recent rows, positive numbers (i.e., $55.24) are displaying as negative numbers (i.e., -$55.24). There is no formula in the cell, just a value that I typed in. I tried retyping it. I tried deleting the row and re-entering, etc. and it still shows up as negative.

Of course, the totals are off as well. What's going on? This is a pretty scary error.