[glennaro]

I recall a quick way to obtain pi accurate to 6 decimal places on the simplest of calculators is to remember 113355. Divide the last three digits by the first three and you get 3.141592. Saved me a few times in the “old days” of hand-held calculators with only the basic functions.

[ajf_in_texas]

You might as well just memorize one more digit and not have to do any division: 3.141592

[silverleaf]

Excellent!