How grading works and results are recorded
Why grading never happens in the browser
The whole point of an Activity is that it gives you a trustworthy record of what your child actually did. If grading happened in the browser, that record could be faked by anyone poking at the page. So instead: your child's device never receives the answer key. It sends what they answered, and our server checks it against the questions and produces the result.
What "recorded" means
Once an Activity is submitted and graded, that result is permanent. It cannot be edited, retried into a better score, or deleted - by your child, by you, or by anyone but a platform administrator in an exceptional case. That's deliberate: a result you can trust is one nobody, including us, can quietly change afterwards.