In SAP HCM Payroll for SAP S/4HANA, wage type fields rate and number can be multiplied in a calculation rule using the MULTI ARN operation. The result of this operation will be stored in the amount field. To set the values in the rate and number fields to zero after the multiplication, the operations ZERO=N and ZERO=A are used1. References =
https://answers.sap.com/questions/9074890/wage-type-for-multiplying-a-rate-with-amount-and-d.html

The calculation rule X018 is used to calculate the average of the wage type based on the cumulative values stored in the AMT and NUM fields. The operation X018 divides the AMT field by the NUM field and stores the result in the RTE field. This operation is usually performed after the cumulation of the wage type values using the ADDCU operation. The X018 operation is relevant for the valuation of time wage types according to the principle of averages, which is used for payroll and leave valuation. References = Payroll Operations, Payroll Schema, SAP HCM Payroll for SAP S/4HANA, Free SAP HCM Payroll for SAP S/4HANA Certification Sample Questions and Answers, Work Schedule Rule

In SAP HCM Payroll for SAP S/4HANA, wage types are used for different purposes. For cumulations, the wage type /101 is used. This wage type represents the total gross amount, which flows into the final payment for the employee. Almost all of these amounts are subject to tax and social insurance contributions. A special feature for Croatia is that the wage type itself receives a CNTR2 split, which is needed to distinguish between domestic payments and work abroad. References = 1