Summary: I love this calculator. I work in finance and am accustomed to a ten-key adding machine. This calculator doesn't operate exactly the same--if you're adding the same number together over and over, you can't just hit the plus button for example--but it does work about like an adding machine. The buttons have about the same placement, so if you're able to use a ten-key without looking, you can do that here.
Summary: I love this calculator! I had one when first starting my career. When in the process of transitioning jobs, I left behind my calculator and I have regretted it ever since. Seven years later, I decided I just couldn't live without it. It's a must have in my book!