My problems with Rspec and Debugging

I have spent the majority of my week trying to figure out errors and learning Rspec. I discovered through the codeship blog they were giving a free course for Rspec for free. That same day I completed the Bloc Rspec section...what a coincidence.

Rspec seems to be a valuable skill I will need on my resume when judging my extensive research on job descriptions.

 Below was given as the Rspec test:

To solve the test, the method "add" had to be defined. Here is the answer I finally figured out using the Bastards book of Ruby. (after an hour of being stumped).

The resolution:

I wish I could go into detail on Rpsec and how it works. I will hopefully be able to in the future when I gain a better understanding. 

Happy coding