Declaring variable
We need to tell the computer that we're
planning to store a number in a variable
before you can actually do it. This is called
declaring a variable.
To declare a variable, you need to know
what kind of information it will store
n (i.e., will it store a number, or a text-string, or
something else) and how you plan to refer to
the variable (i.e., the variable's name).