Contact
If a calculation is wrong anywhere on this site, that is the most useful thing you can report, and it will be fixed the same day.
Report a wrong answer
Every product on this site was computed and checked, but a typo in the prose is still
possible. If a number reads wrong to you, send the page address and what you expected. That
correction takes priority over anything else.
Other things worth sending
A mental-arithmetic method that is clearer than the one we used, an app whose paste limit we
have described incorrectly, or a calculation you looked for and could not find.
How to reach us
Use the form below. There is no phone number and no mailing list.