Base Face Amount + Term Insurance = Desired Death Benefit
That means we only need any two variables to figure out the third.
Guess what we do at my office. We ask for all three. How can this work? Simple, we just give the client much more insurance than he asked for (and he pays for it). Since this is an illustration, we're not bound by the numbers.
So we get to give wrong numbers and make the client buy more. Incompetence pays it seems.