How difficult is it to use Numera?
That's a fair question, and the answer is that it depends on what you're trying to do.
We'll discuss that in a second. Studies show that most people use about 30% of a large application's features.
Do you know anyone who uses EVERY feature of the high-end word processors and spreadsheets out there?
Most people use an application to perform a limited number of tasks.
So, if you want to use Numera essentially as a calculator, then it's easy - just go through the tutorials in the tutorials\expressions\beginning_examples and fast_start
folders that will be created when you install Numera. You'll quickly "get the idea." You can also take the Numera Tour on this site and see for yourself the advantages of using Numera as a calculator. You will also see that using variable names is an easy, natural and expressive way of working with numbers.
If you want to use Numera to write an amortization mortgage calculator, it's more difficult because you will need to learn how to use arrays, structs, looping etc. Numera may inspire you to become a programmer, or maybe you won't have any interest in that.
Either way, it's an extremely useful application and well worth the price.