Why program to add two numbers ?

        That was my first computer C programming lab. Roll number wise we all sat accordingly. I had hardly used computer before that. Lecturer  said write a program to add two numbers. I was scared. I mean how to write? Where to write? Why should we write? Many questions came across my mind. I was shy to ask my doubts. I saw few guys typing something, I dint know what to do. I somehow found courage to ask my classmate who was sitting next to me. I asked her what should we do. She answered even I don’t know. There I got a smile on my face that I have a company. Thanked god. I guess lecturer understood our problem. And told us open so and so editor. Lecturer wrote the program on board and asked us to type it in editor. We typed. Then she said compile using so and so. We did. Then she said run the program using so and so. We did. There came the output Sum = 5. I swear I was happy to see the output. But still my very big doubt was still running on my mind. That was “Why we need to write a program to add two numbers when we already have calculator”. Sounds funny right ?  If people ask to do things without making others understanding why they need to do, it leads to funny doubts like this.