Search:

Do you know what an assignment statement is? It is a statement where a variable is assigned a value:
theVariable = theValue; // assign theValue to theVariable

I do not see any code that assigns...

You missed this question in my last post:
Where is the variable: calc assigned a value?

Its value will be null if it is not assigned a value.

Reaching into another class for a value is a poor...

Where is the variable: calc assigned a value? I do not see where calc is declared or assigned a value in the posted code.