Contact
A wrong result is the most useful thing you can report. Send the page address and what you expected, and it gets fixed.
Report a wrong answer
Every formula here was checked, but a typo in the prose is still possible. If a number reads
wrong to you, send the page and the figures you entered.
Other things worth sending
A convention we chose badly (there is more than one way to treat a tie, or to map a
percentage onto a grade), a French page whose wording is stiff or wrong, 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.