Terms of service
Last updated: October 11, 2026.
These terms are an agreement between you and OpenSlot LLC, a Kentucky limited liability company (Organization No. 1623293), which operates Mathproven ("we", "us"). By using this site or its add-ins you agree to them. If you use Mathproven for a company or other organization, you confirm that you are allowed to accept these terms for it, and "you" means that organization too.
1. Who can use the service
Mathproven is made for businesses and professionals. You need to be at least 18 and able to enter into a contract. Give us an email address you control if you create an account.
2. What the service is
Mathproven provides calculation and verification tools. You enter numbers or open a file in your browser; the tool computes a result and runs arithmetic checks on it. Files you open are processed on your device and are not uploaded to us.
3. Calculation tools, not advice
The tools calculate and check arithmetic. They do not provide legal, tax, accounting, medical, or other professional advice, and nothing on this site is a substitute for a licensed professional. We do not review your documents. You are responsible for the data you enter, for reviewing every result before you rely on it, file it, sign it, or send it to anyone, and for deciding whether a document or format is right for your situation. Reference tables and document templates on this site are general information drawn from the sources cited beside them; laws and rules change and may not be current.
4. Verification certificates
A certificate lists the checks a tool ran and whether each passed. A passing certificate means the listed arithmetic checks agreed. It is not a guarantee that the inputs were correct, that the result suits your purpose, or that any third party will accept it. A result marked "Not verified" failed at least one check and is not presented as correct.
5. Your files and your data
Your files stay yours. They are read in your browser and are not sent to us, so we do not hold copies and cannot recover them for you. You are responsible for having the right to use the documents and data you open, and for keeping your own copies.
Because file contents never reach us, we do not receive patient or other protected information from the tools, and we do not sign business associate agreements or similar data processing agreements for file contents. Whether a browser-based tool fits the rules that apply to you is your decision. What we do collect is described in the privacy policy.
6. Accounts
You can use the free tier without an account. Paid plans need an email address, used to sign in by one-time link. Keep access to that mailbox secure; anyone with the link can sign in as you until it expires. One account is for one subscriber; a Firm plan covers the people in one office.
7. Plans, prices, and taxes
The free tier has limits (shown on the pricing page) that we may change. Paid plans and their prices are shown on the pricing page and at checkout. Prices are in US dollars and do not include taxes; any tax that applies to your purchase is shown at checkout before you pay. A promotional code applies only as described when it is issued, cannot be exchanged for cash, and may be withdrawn before it is used.
8. Automatic renewal and cancelling
Paid plans renew automatically. A monthly plan renews every month and a yearly plan every year, at the price then in effect, charged to the payment method you gave at checkout, until you cancel. Payments are processed by Stripe.
You can change plan, update payment details, or cancel at any time from your account page by choosing Manage billing. Cancelling stops future renewals; you keep paid access until the end of the period you already paid for. If the price of your plan changes, we will tell you by email before the first renewal at the new price, and you can cancel before it applies.
9. Refunds
You can request a refund of your most recent payment within 14 days of that payment from your account page, and it is issued automatically. See the refund policy.
10. Spreadsheet add-ins
The add-ins for Excel and Google Sheets run inside those products, which you use under Microsoft's and Google's own terms. Paid use of an add-in is unlocked by a key from your account page. A key is for the subscriber's own use, expires on the date shown, and can be replaced from the account page while the subscription is active.
11. Acceptable use
Do not use the service unlawfully, attempt to disrupt it or get around its plan limits, copy it or build a competing product from it, or resell it without permission. Do not send us customer files, patient information, or account numbers by email or any other channel; we do not want them and will delete them.
12. Other companies' services
We rely on Stripe for payments, Cloudflare for hosting, and an email provider for sign-in links. Their services are provided under their own terms, and we are not responsible for outages or errors on their side.
13. Our content, your output, and feedback
The site, the tools, the templates, and the text on them belong to OpenSlot LLC or its licensors. We give you a limited, non-exclusive, non-transferable right to use them for your own business while you follow these terms. The documents and exports you produce with the tools are yours to use; they may include a small "Prepared with Mathproven" line. If you send us suggestions, we may use them without owing you anything.
14. Changes to the service
We may add, change, or discontinue tools and features. If we discontinue a paid plan altogether, we will refund the unused part of what you paid for it.
15. Disclaimer of warranties
The service is provided "as is" and "as available", without warranties of any kind, express or implied, including merchantability, fitness for a particular purpose, accuracy, and non-infringement, to the fullest extent the law allows. We do not promise that the service will be uninterrupted or free of errors.
16. Limit on liability
To the fullest extent the law allows, OpenSlot LLC is not liable for indirect, incidental, special, consequential, or punitive damages, or for lost profits, revenue, data, or business. Our total liability for all claims relating to the service is limited to the greater of (a) the amount you paid us in the 12 months before the claim arose and (b) $100. These limits apply whatever the legal basis of the claim, and even if a remedy does not make you whole.
17. Claims caused by your use
If someone brings a claim against OpenSlot LLC because of documents you produced, data you used without the right to, or your breach of these terms, you will cover our reasonable costs and losses from that claim.
18. Suspension and ending
You may stop using the service at any time. We may suspend or close an account that breaks these terms or puts the service or other people at risk. Sections that by their nature should outlast the agreement (including 3, 4, 13, and 15 to 20) continue to apply after it ends.
19. Governing law and disputes
These terms are governed by the laws of the Commonwealth of Kentucky, without regard to conflict-of-law rules. Before starting a legal claim, contact us at support@mathproven.com and allow 30 days to try to resolve it informally. Any claim that is not resolved will be brought only in the state or federal courts located in Kentucky, unless the law where you live requires otherwise.
20. General
These terms, with the privacy policy, the refund policy, and the details shown at checkout, are the whole agreement about the service. If part of them cannot be enforced, the rest stays in effect. Not enforcing a term once does not waive it. You may not transfer this agreement without our consent; we may transfer it as part of a sale or reorganization of the business. We send notices to the email address on your account. We may update these terms by posting a new version here with a new date; using the service after a change means you accept it.
21. Contact
OpenSlot LLC, a Kentucky limited liability company (Organization No. 1623293)
1501 South Greeley Highway, Ste C #1526, Cheyenne, WY 82007, USA
support@mathproven.com