I spent a year and a half entering numbers into my spreadsheets and other software on my Microsoft Surface Book. I've known how to use the 10th key for most of my life. It never occurred to me that I could get a separate 10-key numeric keypad for this job. This key 10 works for me. It's just big enough to fit my hands comfortably. The keys have the same tactile feedback as a regular keyboard, and the 5-key has a nice centering bump. It even has a button to bring up the built-in Windows calculator. It connected to my Surface Book with no issues. I just wish I had it all the time. That