Arithmetic derivation may be used with Single Value Derivation or Multivalue Derivation rules
1. Choose Derivation Rule, select the attribute, check expression, and conditions (see Derivation Rule).
2. When condition is TRUE (or FALSE), select the Attribute radio button. Then click the Formula Table button.
3. In the Formula Table, the Type is selected as String Concatenation as default. Change this selection to Mathematical Formula.
4. Click to add as many rows as required.
5. Enter either an Entity/Attribute OR a Fixed Value in each row. Choose the operator for each row, including parentheses where necessary. Click Preview to see the formula. Save the Formula Table.
6. Save your rule to complete.