Contact Us
Use this contact form to report a mistake in a lesson or a solution, to ask a question about the site or our apps, or simply to send us a message. We answer every message as soon as we can.
When should you use the contact form?
Write to us first to report an error, such as a typo in a formula, a wrong answer in a solution page or a link that no longer works. You can also ask a question about your account or tell us which grade or chapter you would like to see next.
How to write a helpful message
Give the address of the page and the number of the exercise or the question. If the problem is about the display, tell us which device and browser you use. Never send a password or bank details.
Before you write
Many answers are already on the site: the math lessons, the worksheets with solutions and the tests with answer keys cover every grade from 1st grade to AP courses.