fx-991MS
Paraphrasing the movie Full Metal Jacket, this is my calculator. There are many like it, but this one is mine. It is my life. I must master it as I must master my life. Without me, my calculator is useless. Without my calculator, I am useless.

Or at least it was that way during my university years. I used to know every funtionality and button of this Casio fx-991MS calculator. What’s more, I used to know what I was doing during the calculation process. Now, I see it and it looks like an old Chinese manuscript to me. Of course I recognize every term on it, but in the end, I only use the +, – and = buttons. It’s a pitty all these forgotten and unusued maths in my life. I should start using it againg, for real.