Mathematics Expert

What you'll do

You write proof-based and computational problems with complete, rigorous solutions, then verify AI-generated solutions line by line, looking for logical gaps, unjustified steps and calculation errors. You classify the types of error so the project team can see where models fail, write grading rubrics and reference solutions at a consistent difficulty, and review other experts' problems for correctness, clarity and originality.

The ad frames this as training and evaluation on advanced mathematical reasoning, so expect the problems to be hard and the error classification to matter as much as the solving.

Who fits

• A Master's or PhD in mathematics, or a Bachelor's plus 2+ years of relevant experience
• A strong command of at least one core area: analysis, algebra, number theory, probability, combinatorics or geometry
• The ability to write clear, rigorous proofs
• Excellent written English and independent, deadline-driven working
• Preferred: research or competition experience, tools such as Python, Mathematica or Lean, and teaching or problem-writing experience

What it pays

Rex.Zone states USD $75–125 per hour, adjusted by country of residence. The $75 floor is higher than the floor on any of the chemistry, physics or statistics listings Rex.Zone has posted alongside this one. The adjustment method is not published, so the top of the range may not apply to every location, and the ad does not say how often or by what method you are paid.

Worth knowing

Good:

• Open worldwide with no country restriction listed
• A Bachelor's with two years' experience can qualify, which is a rare route in at this level
• Problem writing and error classification use real mathematical skill
• A high minimum rate for the group

Less good:

• Country adjustment is not explained
• Rigour is the bar; vague or unjustified steps will be caught in review
• The ad gives no weekly hours or task volume
• Payment depends on verification and on sanctions, export-control, tax and employment rules, and the contractor agreement covering ownership and licence terms was still marked "to be confirmed by Rex Legal"

About this listing

Posted on the Rex.Zone expert portal (also RemoExperts) on 1 October 2026 and read from the portal on 29 October 2026. The pay band, qualifications and responsibilities are Rex.Zone's own text. The portal lists no skills for this role. Applications go through the portal, which sits behind an entry exam and verified-user checks described on the company page. See Rex.Zone.