Is it Possible to call a method which is in another page

yes you can call that method.

 

firstly create an instance for that class in which that method is written and then call by objectname.methodname.

 

classMethod testm= new classMethod();

testm.Addition(); 

Technically yes, those are just methods.

 

Usually if I encounter such a request, there is a design flaw. Shouldn't the code you want to access in two different places be somewhere else available instead?