A user asked how to change the amount of decimals showing on a Money field from two to three on a report.
Rich,
Click here for an article about the Report Designer that has the link to download it and also some tutorial videos of how to use it. When you are editing your report, best practice is to edit a copy of the original so that if you make undesirable changes you can revert back.
To change the number of decimal places, click the Money field (in your case your Unit Margin field), and then click the white arrow to edit it. You'll want to edit the Format String. Enter this into the field: {0:$0.000}
See my screenshot below.
Hope this helps!
Jason