# Implementing the final step

We shall now implement a rule that calculates the total and one that create the subscription we propose to the end user.

![](/files/-M-FW_k29zDpQs2p6634) In the rule above, we have to use custom code as when working with java Bigdecimal class (which we shall use when working with financial amounts) the standard functions do not work.

![](/files/-M-FW_k4dmkLklLkxg8i)

In the second rule, we use the definitive price we create before. in the picture shown below, we can see an example of the test server we shall present in the next tutorial

![](/files/-M-FW_k67qGbVYrUfvVe)

![](/files/-M-FW_k83RyEVq2URbg-)


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