Build an answer key for an assignment

Updated 19 September 2026

An answer key belongs to an assignment, and you make one by handing over a single blankcopy of the worksheet. The grader solves the whole paper and gives you back one editable row per question: the question, the correct answer, the working, the points, and an optional note about how to mark it. You read it, fix anything it got wrong, and every paper graded into that assignment afterwards is marked against that fixed key rather than the answer being worked out again from each student’s handwriting. Building a key does not count against your graded items, so there is no reason to ration it. Assignments and answer keys are a paid feature; grading without one is not.

Setting one up

1
Make the assignment first
Open Assignments, press New assignment, name it, set its type and tick the classes it went to. Naming it is the whole of step one.
2
Upload one blank, unfilled copy
On the assignment page, photograph or upload one blank copy of the worksheet, the one nobody has written on. A PDF or a set of photos both work, up to 8 pages.
3
Wait about a minute while it solves the paper
It works the whole paper out and comes back with one row per question. The screen says so while it runs: Building the answer key, this can take up to a minute.
4
Read the key and fix anything it got wrong
Read it. Every row is editable, rows can be deleted, and rows can be added by hand. This is the step that makes the key worth having, and it is the only step nobody else can do for you.
5
Grade the class into that assignment
From then on, every paper graded into that assignment is marked against the saved key rather than the answer being re-derived from each student’s handwriting.

What a key changes at grade time

One fixed set of answers: Every paper is marked against the same thing, rather than the correct answer being re-derived from each student’s page.
Your points, not inferred ones: The points on each row are what that question is worth, so the totals match the paper you handed out.
Per-question instructions: The free-text rubric on a row is where you say how to mark that question: whether working is required, whether units count, what partial credit looks like.

What this will not do

It reads a blank, not a completed paper. Hand it the unfilled copy. A page with a student’s working on it is a paper to be graded, not a key, and using one as the key teaches the assignment that student’s answers.

Up to 8 pages. The blank is read as one unit, so it is capped the same way a single worksheet is. A longer paper than that is beyond what one key covers.

Check it before you trust it. A key is the grader’s own reading of the paper, so an error in it is an error on every student. Rows it was unsure about are flagged for exactly this reason. This is the five-minute job that pays for itself across thirty papers.

It is per assignment, not per class. The key lives on the assignment, and an assignment can be given to several classes. A different worksheet needs its own assignment.

If the key cannot be loaded, the paper is still graded. A failure to read the key does not fail the grade: the paper is marked without it, the way an untagged paper is. That is the safe direction, but it means a mysteriously inconsistent set is worth checking against the assignment page.

Common questions

Does building an answer key use up my graded items?

No. Solving a blank worksheet is not a graded student paper, so it is not charged to your included items. It does count towards the platform-wide daily ceiling that exists as a cost backstop for everyone, but that is not a plan limit and you will not notice it.

Do I need an answer key at all?

No. The grader works each problem out on its own, which is what lets it accept a half, 0.5 and 50% as the same answer and mark a student right who took an unexpected route. A key makes a class set faster and steadier, because every paper is then marked against one fixed set of answers instead of the answer being re-derived from thirty different handwritings.

What is in each row?

The question number, the problem as it was read off the page, the correct answer, the working behind it, the points that question is worth, and an optional free-text rubric telling the grader how to mark that particular question. A row it was unsure about is flagged, so read those first.

Can I write the key myself instead of photographing a blank?

You can edit every field and add rows by hand, so in practice yes, though the quickest route is still to let it read the blank and then correct it. There is no separate paste-a-key box.

What is the equivalent for essays?

The writing prompt and the rubric, both saved on the assignment. An essay assignment will not grade without them, and saving them on the assignment is what makes every essay in the set score against the same thing. The rubric is copied onto the assignment when you attach it, so editing your library later never changes a grade you already gave.

What if the key is wrong on one question?

Edit that row on the assignment page. Papers already graded keep the grade they were given, so re-grade them from Review if you want the correction applied, which is charged the same way as grading new work.