Casio Men's Vintage CA53W-1 Calculator Watch from Amazon
Brief overview of my experience with the watch. I show a close up of buttons and thats it. Comment if you want to see more or have any questions. The calculator feature is pretty straight forward. Click over using the top right side silver button until you get to the 0. From there type what you like to perform a equation. My focus was more so on the ability of the watch to respond to force applied to the start and stop function. Its decent for intervals and basic clocking. It aint FAT for you track people.