It's an easy thing to misunderstand especially if you are into math. Next time, try using '-' instead. Like 6 - 6s - 7s... It is easy to type and can be substitute for the word to. No need to get frustrated or feel like others are stupid, everyone think differently and we all come from different backgrounds.... now to the real matter.
I do like a bigger screen that's why I really want my ideal setup to come true:
iPad mini for reading and everything else. Apple Watch to be able to connect with the iPad mini and answer phone calls and writes messages. iPad Pro for light computer tasks and perhaps an iMac at home to run adobe creative suites. My ideal setup would eliminate the iPhone 100%. I thinkI'll really enjoy this setup I doubt Apple will go this direction though......
So now, my setup will consist of the iPhone 6s Plus, iPad Pro and the Apple Watch. However, I would love to swap out the iPhone with the iPad mini. I feel like for the watch to be able to make phone calls independently is so crucial and can streamline my entire operation.