Children's Privacy Notice

Version 1.0.0 · effective 12 September 2026 · part of the Privacy Policy

This notice is for parents and guardians. It says what Erudia does when a learner is under 13, and what a parent can do. Erudia is written for learners 13 and older and is not directed to younger children, but a mathematics site is used by all ages, so we plan for it.

The age screen comes first

Before anyone can create an account, and before a guest's first synced action, Erudia asks for a birth month and year. The question is neutral: it does not say what answer unlocks anything, and a cookie stops the back button from asking again. The answer stays on the device. A learner whose answer computes to under 13 is taken to the guest experience described below.

What a learner under 13 can do

Everything that teaches: lessons, reviews, worksheets, practice generators and the knowledge map, as a guest on their own device. Progress is stored in the browser only and is never sent to us. Reviews are scheduled and difficulty adapts on the device, which is what the lessons need to work.

What is off: creating an account, choosing a display name, appearing on a leaderboard, duelling other learners, and posting, voting or flagging in the community. Those features collect or display personal information, and we do not collect personal information from a child under 13 without a parent's verifiable consent.

If we learn an account belongs to a child

If a stored birth date, a parent, or a learner tells us an account belongs to someone under 13, we stop syncing it, clear the display name, withhold the account from leaderboards, and block community writes on the server. We then email the address on the account with this notice and two choices for the parent:

Delete. We erase the account and everything in it. The learner can keep using Erudia as a guest.
Consent. A parent gives verifiable consent by one of the methods the law allows (a text message or email confirmed by a second step, or an identity check), after which we restore the account with the community features still off. The parent can withdraw consent, review the child's data, or ask us to delete it at any time.

What we would collect from a child with consent

An email address for the parent and for sign-in.
Learning progress and review state, to run the lessons.
Learning events (timing, correctness, hints) linked to the account, used to run the review scheduler; with consent, also used in aggregate to improve the engine.
Records of the consent itself.

We would not collect or display a screen name, would not show the child on any leaderboard or to any other learner, and would not disclose the data to anyone except the providers that run the service (listed in the Privacy Policy). We would keep it only as long as the account is open and then delete it, per the retention schedule in that policy. We do not condition a child's use on giving more information than the activity needs.

Learners between 13 and 18

For a learner whose stored age is under 18, the streak nudges, public leaderboard visibility and (when they exist) push notifications are off by default. The learner can turn each on in Settings. Nothing about a learner under 18 is used for advertising, because nothing about anyone is.

A parent's rights

A parent can review what we hold about their child, have it deleted, or withdraw consent, by emailing erudia@erudia.org from the address on the account or by using the privacy request desk. We verify that the request comes from the parent before acting on it. There is no charge, and we answer within 30 days.

Where else this applies

The United Kingdom's Age Appropriate Design Code, the EU's rules on children's consent, and the minors' laws of several US states set their own ages, between 13 and 18. Where a learner is under the age of digital consent in their country, we rely on no consent-based processing for them at all: analytics consent is off by default and everything else rests on the contract to provide the lessons. The country table we use is in our configuration and is corrected as we learn of errors.