Same skill as question 10 — Number clues: digit puzzles and divisibility — new numbers, no hints from the site, generated and marked by code. Check you can do a new one now; holding it a week later is a separate test, and the plan schedules that.
This demo stores nothing: no account, no cookie, and your answer is not kept. Registered children get this check on every miss, and their result is recorded next to the question it came from.