I use Excel 2013. I have a table with 2000 rows. One column is calculated by subtracting two 2-decimal columns from another 2-decimal column. Each of those columns are typed in and there is no odd data.

There are only 16 examples of this, but it is weird - this is what the column holds for those rows:

Amount Due
$(0.0000000000104773793807578000)
$(0.0000000000072759576141834300)
$(0.0000000000036379788070917100)
$(0.0013592233008239400000000000)
$(0.0021359223301260500000000000)
$(0.0000000000006821210263296960)
$(0.0029999999956089600000000000)
$(0.0000000000291038304567337000)
$(0.0000000000072759576141834300)
$(0.0000000000072759576141834300)
$(0.0000000000072759576141834300)
$(0.0000000000072759576141834300)
$(0.0000000000011652900866465600)
$(0.0000000000372892827726901000)
$(0.0000000000000248689957516035)
$(0.0000000000003979039320256560)
$(0.01) this is a subtotal row


Any idea why this happened?