Funny. If you're going to stop there, you should end it with a 7 to minimize errors.
The above, while technically true, is exactly as pointless as it sounds. The error is lower with a 7 than a 6, but if either of them is an acceptable approximation, the difference is irrelevant.
Obviously, I know this, but it rhymes better with 6 at the end (I am Polish).
There is only few instruments I have been around in my life that can actually measure this difference. I have 6.5 digit Voltmeter which would almost be able to detect it in certain situations if I somehow contrived the experiment, but not in any practical measurement where I actually had to calculate anything.
Lots of people memorize more digits of pi than they need, just because it's fun. I've noticed that most who do this stop at 50 digits after the decimal point. When I was younger I knew 250 digits, now I'm lucky to remember beyond 100.
