Privacy for arithmetic practice
Last updated: 10 October 2026. This is the privacy notice for Turnmori custom arithmetic practice. There are no accounts, advertisements, external fonts, external images or third-party analytics SDKs in this version.
Your practice stays in your browser
Questions and answers are processed in your browser. We do not save answers, question history, names or free-text input. Only your selected settings and analytics choice, plus a first-completion time with a return-reported flag if analytics is on, can be saved in this browser's local storage. There is no user or device ID.
Storage may be blocked or damaged. The page reports this, and practice remains available. A shared browser can expose saved settings and the first-completion marker to its other users.
Missed-question review
The optional review contains incorrect and timed-out questions from the current set only. It stays in this open page’s memory and is not saved or sent. Starting another set, choosing Change settings, reloading, deleting device data or turning off usage sharing clears it. Clearing it during practice also stops review collection for that set.
Settings links are your choice
Copy settings link includes only the operation, minimum, maximum, question count and seconds per question. These values are in the address fragment (after #), which is not sent in the page’s HTTP request or usage counts. Anyone with a copied link or bookmark can read those settings. Links contain no answers, questions, history or usage choice. Opening a link updates the setup fields without starting practice or changing saved device preferences. Settings can be saved when you choose Start practice. Delete device data also removes a settings link from the current address in open tabs of this tool; previously copied links and bookmarks still work and can restore setup fields when opened. They do not restore deleted device data.
Usage sharing is optional
Sharing is off by default. You can use all practice features without it. Only after your choice, this page can send these same-origin events:
- A page view when sharing is accepted or when a page is opened with a saved choice.
- A practice start and a practice completion.
- Active session duration with a completion, when it is no more than one hour. Longer durations are omitted from the time total rather than shortened.
- A device-declared return signal when a new practice starts 1–7 days after the first saved completion, at most once for that saved marker.
The payload contains only the fixed tool name, version, variant, event name and optional session duration. It contains no answers, questions, selected ranges, names, free-text input, cookies or user IDs. Failed transmissions show a notice; there is no retry queue.
The service stores daily event counts and duration sums, not individual practice histories. These are exploratory totals, not unique people, individual funnels or an exact retention rate. Shared devices, storage deletion, multiple tabs, bots and the choice to consent can affect them.
Retention and withdrawal
The active aggregate table is configured to keep the most recent 90 UTC dates (today and the preceding 89 dates), with daily cleanup. A live scheduled cleanup run has not yet been verified. Cloudflare D1 on the current Free plan can restore an earlier database state for up to 7 days, so removed aggregates can remain recoverable for that additional window. After the experiment ends, we stop collection and aim to delete its active aggregates promptly, no later than 23 days after it ends, then track the 7-day recovery window toward a 30-day closure target. These future actions have not yet happened. A recovery-window expiry estimate is not proof that every physical copy held by the provider has been erased.
Turning sharing off stops future requests, aborts requests still in progress, and removes the three kinds of saved device data. An in-flight request may already have reached the service before it can be aborted. Turning sharing off cannot undo counts already received. Because anonymous totals cannot be tied to you, individual removal from those totals is not available. We save withdrawal as false before deleting device data, so a deletion-only failure does not revive old consent on reload. Failed deletion is reported. If both saving withdrawal and deleting the old choice are blocked, sharing is off only in the current tab and may resume after reload; the page warns you to clear this site data through your browser before returning.
Use Delete device data to remove saved settings, analytics choice and the return marker and reset the setup fields. This also turns sharing off in other open tabs of this tool. The current practice can continue. Settings may be saved again when you start another practice, without turning analytics on. A new completion can create a fresh local return marker only after you explicitly turn sharing on again.
Technical delivery and hosting
Your browser's requests require the hosting provider to process technical data such as an IP address. The release configuration disables persistent Workers Logs, traces and Logpush for this application. That configuration has not yet been verified on a live deployment; past application error logs will not be available when these features are off. This does not disable or audit the provider's separate security and delivery processing. We do not claim that the hosting provider never processes or retains technical request data. The application does not put IP addresses or user-agent strings into its usage aggregates.
Search providers may process searches and clicks under their own policies. This version does not connect a search click to an individual practice session.
Changes
If hosting, analytics, advertising or data practices change, this notice and the release review must be updated before that version is published.