Contact C:Math

Last updated: 2026-05-29

C:Math is a free bilingual math practice game built and maintained by a single developer as a hobby project. We are happy to hear from learners, teachers, parents, translators, and anyone who has spotted a bug or a math error. This page explains how to reach us, how long replies usually take, what topics we can help with, and what we cannot take on. Please read the relevant section before sending an email so that we can give you a useful answer on the first reply.

1. How to Reach Us

The primary and only contact channel for C:Math is email. Please write to rin238238@gmail.com. Because C:Math is a hobby project maintained in evenings and weekends, we do not offer phone support, live chat, social media direct messages, or a contact form. Email lets us read your message carefully, look at the relevant code or page, and give you a complete answer in one round trip instead of several short back-and-forth chats.

If you want to copy the address by hand, here it is as plain text:

rin238238@gmail.com

Writing in English or Korean is both completely fine. We can also read short messages in Japanese, French, German, Spanish, Portuguese, Italian, Dutch, and Chinese, but a reply in those languages may take a little longer because we usually translate carefully before sending it out.

2. Response Times

Our best-effort target for most inquiries is a reply within seven calendar days. Privacy and account-deletion requests are prioritized above everything else and are typically answered within two business days, because they involve user rights under the Korean Personal Information Protection Act (PIPA) and equivalent regulations elsewhere. Bug reports that include clear reproduction steps are usually answered faster than vague reports, because they require less back-and-forth before we can confirm and fix the problem. If a week has passed and you have not heard from us, please feel free to send a short follow-up email; sometimes a message gets caught by a spam filter or buried under heavier traffic.

3. Topics We Reply To

• Bug reports (calculator error, grading mistake, broken link)
• Content correction (typo, math error in an explanation, wrong unit)
• Privacy or data-deletion request (see Privacy Policy)
• Accessibility issue (screen-reader bug, contrast complaint, keyboard navigation gap)
• Partnership or collaboration (educational organizations, school licensing, research)
• Translation contribution (we ship 10 UI languages and welcome help maintaining quality)
• General feedback or feature request

4. Topics We Cannot Answer

• Math homework help — instead, please try the free practice tools or the math concept guides on the site
• Custom math curriculum for institutions — building bespoke courseware is out of scope for a hobby project
• Sponsored content or paid promotion — we do not run sponsored placements, paid reviews, or affiliate insertions

If you write to us about one of these topics, we will usually send a short polite note pointing you to a public resource rather than a long custom reply. Please do not take that as a sign that we are uninterested — it just means we have to protect the limited time we can spend on the project.

5. Bug Report Template

Bug reports with the following six fields are answered fastest because we can usually reproduce the problem without asking follow-up questions. You can copy and paste this block straight into your email:

Subject: [Bug] short description

URL where the bug appeared:
What I did (step by step):
What happened:
What I expected:
Browser + OS + screen size:
Screenshot (attached if possible):

If you cannot reproduce the bug consistently, that is fine — just describe what you remember and we will work from there. Even a single screenshot of the wrong answer is more useful than no report at all.

6. Privacy and Data Requests

Under our Privacy Policy, you may request a copy of your data, ask for corrections, or delete your account at any time. For deletion or data-access requests, please email rin238238@gmail.com from the address registered to the account, or include enough information for us to verify ownership. Requests are processed within 30 days, in line with the Korean PIPA standard. The fastest path is usually self-service: open Settings, then Account, then Delete, and your account and learning history will be removed immediately. Email is the right channel when you want a written confirmation, when you cannot log in, or when you are exercising a legal right that requires a paper trail.

7. Mailing Address

C:Math is run as a sole-proprietor hobby project and we do not publish a physical mailing address on the public site. For legal correspondence that genuinely requires a postal address — such as a formal notice from a lawyer, regulator, or court — please send an initial email to rin238238@gmail.com describing the matter, and we will share the mailing address privately by reply.

8. Closing

Thank you for taking the time to write. Every email is read by a human, usually the same person who wrote the code you are mailing about, and your feedback is one of the most useful inputs we have for deciding what to fix next. Whether you are reporting a typo, suggesting a feature, or pointing out a math mistake we should be embarrassed about, we appreciate the effort, and we will get back to you.