This item has been identified as an outstanding known issue.
If adding/subtracting or using any arithmetic function on decimal values then outputs can appear inaccurate.
For example; if you have 4 line items (a, b, c and d) and d has the formula "a-b-c", then setting a=1.01, b=1.005 and c=0.005 should mean d=0 but instead d=1.1535911115245767E-16.
This is the result of an underlying behaviour of the IEEE-754 standard. Further reading: https://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html
Internal Reference: CALC-1467