Write formative comments for math errors in primary school

Context

A primary school math teacher (grades 1–6) who wants to write useful feedback comments on tests or homework — comments that help the student understand what went wrong and how to fix it, not just "incorrect."

Paste first

Before opening the model, have ready:

• A description of the error the student made (not the student's name — describe the mathematical error)
• The grade level
• The learning objective or content being assessed
• Whether you want the comment written in the notebook/test or said out loud

Privacy rule: Describe the math error without mentioning the student's name, ID number, or any identifying information. You can say "a grade 5 student made this error" — nothing more.

Act as a primary school math teacher who knows how to give formative feedback: not just pointing out that something is wrong, but helping the student understand why and what they can do to fix it.

I'll describe a math error I saw in a student's work from {{grade level, e.g. "Grade 5"}}. Help me draft a feedback comment.

**Content being assessed:** {{learning objective or content, e.g. "multiplication of fractions"}}

**Description of the error:**
{{describe the math error in detail — e.g.: "the student added the numerators and denominators separately when multiplying fractions: solved 1/2 × 3/4 as 4/6 instead of 3/8"}}

**Comment format:** {{written in the notebook / spoken / both}}

**Length:** {{brief (2-3 sentences) / moderate (4-5 sentences)}}

What I need:
1. A comment that explains why the procedure doesn't work, without using technical language the student doesn't understand yet.
2. A concrete question or suggestion that invites them to try again.
3. If possible, a small example that shows the difference between the incorrect and correct procedure — without giving them the answer directly.

Don't use phrases like "great effort" or "you're on the right track" if the error is conceptual. Be honest and useful.

Expected output

When you multiply fractions, the denominators don't get added — each one has its own job. Try this: how much is half of half of something? If you have 1/2 of 1/2 of a pizza, do you end up with more or less than 1/2? That's exactly what 1/2 × 1/2 means.

Try 1/2 × 3/4 again thinking about that: how much is half of 3/4?

Watch out for

• Describe the error, not the student's failure. The model may use language that sounds like blame ("you failed at", "your mistake was"). Replace it with process language ("in this procedure", "at this step").
• Don't paste the student's name, ID number, or any identifying data when describing the error. If multiple students made the same error, you can use the same base comment with minimal adjustments.
• Comments that are too long don't get read by primary school students. If the model produces 8 sentences, ask it to reduce to 3-4 without losing the core idea.

Suggested iteration

If the comment sounds too abstract for the grade level, ask: "Rewrite the comment using a concrete numbers example that a {{grade}} student can visualize easily — something everyday like pizza slices, marbles, or game points." If you want the same comment in an oral version to say in class, ask: "Adapt the comment to be said out loud, in 2 sentences, while the student has the test in front of them."