This function is used to simple calculations in two fields built in business rule. It is an interesting functionality to be noted in Microsoft Dynamics CRM 2013 and this will be a great feature for a lot of users in our client base that are not too technical. It is used to developer’s help in order to implement very simple business.
Following steps given below:
1. Open CRM System and click on (Settings>>Solutions>>Entities>>Select any entity name for example (Account entity) then Business Rules.)
Add a new rule first rule is “Calculation Result” and second rule is “Final Result” in Account entity.
2. Follow second rule “Final Results” and define one condition and two actions- select two options set field “Equation match ” is set “No” then set the value of the decimal number field to “0” and hide field.

3. Follow first rule “Calculation Results”-multiplication one more action to ensure that the “Final Result” field is show if “Equation match “=”Yes”

4. On form, when you select “Yes” in “Equation match” the calculation will be performed, a result will be set in the “Final Result” field, and the “Final Result” will be show.

5. Final steps, If you select “No” on the form then in Equation match” no calculation will be performed, the value zero”0” will be set in the “Final Result” field, and the “Final Result” will be hidden.
