Frequently asked questions
Is Num Drill free?
Yes. Num Drill is free at launch and has no plan to introduce a paid tier. There is no premium upgrade, no pay-to-unlock-levels mechanic, and no subscription. If we ever change that, current features stay free.
Do I need to create an account?
No. There is no login, no email collection, and no signup form. Tap a profile pill (or use the Guest profile) and start a quiz.
Where are profiles stored?
On the device, in the browser’s local storage. We never copy roster, profile, or progress data to a remote server. Quiz results (the questions and your child’s answers) are sent to our server when a quiz is completed, so we can grade and store the score — but they aren’t tied to a remote account.
Can multiple kids use the same device?
Yes. Each kid gets their own profile pill at the top of the home screen with a custom emoji and color. Tapping a pill switches everything (weak-fact tracking, personal bests, mastery grid) instantly. No sign-in, no password.
What grades is Num Drill for?
Roughly grades 2 through 6. The six levels per operation are pitched a couple of grades ahead of typical curriculum, so a confident 3rd grader will start at level 3 of multiplication (full 1–12 tables) and a strong 5th grader will start at level 4 of fractions (all four ops on fractions). Younger kids can start at level 1 of any operation; older kids who need more challenge can push to level 6.
Does Num Drill work offline?
The app shell is cached as a Progressive Web App, so it loads even when the network is flaky. Submitting a quiz to record the score requires connectivity. If your device has no network, the quiz will still play but the score won’t be recorded.
Can I install Num Drill on my iPad’s home screen?
Yes. In Safari on iPad, tap Share, then “Add to Home Screen.” The app installs as a standalone PWA with its own icon and full-screen mode (no Safari URL bar). The home-screen icon launches you straight into the practice app, not the marketing site.
What data does Num Drill collect?
Per quiz, we store: the operation and level, the questions asked, your child’s submitted answers, per-question timing, the display name typed into the local profile pill, and the requesting IP address and user-agent for abuse prevention. We do not collect emails, addresses, parent contact info, payment information, or any personally identifying information about your child. There are no third-party trackers.
How does the adaptive difficulty work?
When your child gets a fact wrong, that fact gets a higher weight in their next quiz, so it surfaces again sooner. Correct answers slowly decay the weight back. The mechanism is per-profile, per-operation, and runs entirely on the device.
Why is the answer graded reduced?
For fractions, we accept any equivalent form. If the reduced answer is 1/2, your child can type 2/4 or 5/10 and still get credit. The goal is fluency, not a gotcha about simplification.
I have a question that isn’t here
We’ll add to this page over time. For now, the parents page covers the broader picture and the methodology page covers the research.