Privacy Policy

Last updated: September 13, 2026

Introduction

DecimalHero ("we," "our," or "us") is committed to protecting your privacy and providing a secure, educational experience. This Privacy Policy explains how we collect, use, disclose, and safeguard your information when you visit our website decimalhero.com (the "Site"), use our interactive math practice tools, including significant figures practice, decimal places exercises, negative numbers quizzes, integral practice, and other educational features, and use the DecimalHero Quick Math Chrome extension. We operate on a privacy-first principle: we collect minimal data, never sell your information, and use data only to improve your learning experience. Please read this privacy policy carefully. If you do not agree with the terms of this privacy policy, please do not access the site.

Information We Collect

Personal Information

We do not require account creation or login to use DecimalHero. You can access and use all our practice tools, learning guides, and educational resources completely anonymously. We do not collect personal information such as names, email addresses, phone numbers, or any identifying data unless you voluntarily provide it through our contact form or feedback form. Any information you voluntarily provide is used solely to respond to your inquiry or improve our services. We never require personal information to access our educational content.

Feedback Form Data

When you submit feedback through our question generator feedback form, we collect the following optional information:

• Learning feedback: Whether the practice session helped you learn (Yes/Not really), improvement reasons if applicable (e.g., easier questions, harder questions, different topic), and optional topic suggestions
• Feedback text: Any written feedback you choose to provide
• Topic suggestions: Suggestions for new math or science topics you'd like to see
• Feedback tags: Categorization tags you select (e.g., bug report, feature idea, question unclear)
• Email address: Optional email if you choose to provide it for follow-up purposes

In addition, we automatically collect the following metadata to help us understand context and improve our services:

• Session ID: A unique identifier for your feedback session (not linked to your personal identity)
• Questions answered: Number of questions you answered before providing feedback
• Game type: The type of practice game you were using (e.g., integrals, significant figures, decimal places)
• Difficulty level: The difficulty setting of the practice session
• Current route: The page URL where you submitted feedback (e.g., /subjects/math/number-systems/significant-figures/counting/practice)
• Game score and streak: Your current game score and streak at the time of submission (if applicable)
• Device type: Whether you're using a mobile or desktop device
• Timestamp: When the feedback was submitted
• User agent: Browser and device information for technical support purposes
• IP address: Collected for security and fraud prevention (anonymized and not used to identify individuals)

How We Process Your Feedback

When you submit feedback, it is processed as follows:

1. Submission: Your feedback is sent securely to our servers via HTTPS encryption
2. Server Processing: Our backend API receives and validates your feedback data, ensuring it meets our security requirements
3. Data Storage: Feedback data is stored securely on our servers with appropriate security measures
4. Analysis: We analyze aggregated feedback patterns to identify common issues, popular feature requests, and areas for improvement
5. Product Improvement: Feedback is used to prioritize development work, improve question generators, fix bugs, and add new features

Important: All feedback submissions are processed automatically. We do not manually review individual feedback submissions unless you specifically request support through our contact form. Your feedback is aggregated with other submissions to identify trends and patterns that help us improve DecimalHero for all users.

This metadata helps us understand which features need improvement and provides context for your feedback. All feedback data is stored securely and is only used to improve DecimalHero. Your optional email address is only used to follow up on your feedback if needed, and is never shared with third parties. We do not use feedback data for advertising, marketing, or any purpose other than improving our educational services.

Automatically Collected Information

When you use our Site, we automatically collect certain technical information necessary for the website to function properly. This information is anonymized and aggregated where possible:

• IP address: Collected for security and fraud prevention. We anonymize IP addresses and do not use them to identify individual users.
• Browser and device information: Browser type, version, operating system, and device type to ensure compatibility and optimize your experience
• Usage analytics: Pages visited, time spent on pages, and navigation patterns (anonymized and aggregated)
• Referring website: How you found our Site (e.g., search engine, direct link)
• Game session data: Scores, streaks, and practice progress are stored locally in your browser only. We do not track or store this data on our servers.

Important: All game progress, scores, and streaks are stored exclusively in your browser's local storage. We do not have access to your individual practice sessions, scores, or learning progress. This data never leaves your device and is automatically deleted if you clear your browser data.

How We Use Your Information

We use the collected information for the following purposes:

• To provide and maintain our free educational services, including practice games (significant figures, decimal places, negative numbers, integrals) and learning guides
• To analyze aggregated, anonymized website usage patterns to improve user experience and identify popular features
• To respond to your inquiries and provide customer support when you contact us
• To process and analyze feedback to improve our question generators, practice tools, and educational content
• To understand user needs and prioritize product improvements based on aggregated feedback patterns
• To detect, prevent, and address technical issues, security threats, and fraudulent activity
• To ensure compliance with applicable laws and regulations
• To protect the security and integrity of our Site and prevent abuse

We never use your data for: Targeted advertising based on your personal information, selling your data to third parties, creating user profiles for marketing purposes, or tracking you across other websites.

Cookies and Tracking Technologies

Google Analytics

We use Google Analytics to analyze website traffic and user behavior. Google Analytics uses cookies to collect information about your use of our Site. This information is used to compile reports and help us improve our services. You can opt out of Google Analytics by installing the Google Analytics Opt-out Browser Add-on.

Google AdSense

We use Google AdSense to display advertisements on our Site. Google AdSense uses cookies and similar technologies to:

• Show ads based on your visits to our Site and other sites on the Internet
• Measure the effectiveness of ads
• Provide personalized advertising content

You can opt out of personalized advertising by visiting Google Ad Settings or by visiting www.aboutads.info/choices/.

Managing Cookies

You can control and manage cookies through your browser settings. Most browsers allow you to refuse cookies or delete them. However, disabling cookies may affect the functionality of our Site.

Data Sharing and Disclosure

We do not sell, rent, trade, or otherwise transfer your personal information to third parties for marketing or commercial purposes. Your data is yours, and we respect that. We may share information only in the following limited circumstances:

• With your explicit consent: Only when you have given us clear, informed consent to share specific information
• To comply with legal obligations: When required by law, court order, or government regulation
• To protect rights and safety: To protect our rights, property, or safety, or that of our users or others, including fraud prevention
• With trusted service providers: With third-party service providers who assist us in operating our website (such as hosting providers, analytics services like Google Analytics, and advertising services like Google AdSense). These providers are contractually obligated to protect your information and use it only for the purposes we specify
• Business transfers: In the event of a merger, acquisition, or sale of assets, your information may be transferred, but you will be notified and your privacy rights will continue to be protected

Third-party assets: The WhatsApp icon in our share features is from Vecteezy (vecteezy.com); its use is subject to Vecteezy's Terms of Service. See our Terms page for full attribution. Third-party services: Our Site uses Google Analytics and Google AdSense. These services have their own privacy policies. We do not control how these third parties use your information, but we choose these services because they are industry leaders in privacy protection. You can opt out of Google Analytics tracking using browser extensions or settings.

Data Security & Protection

We implement industry-standard security measures to protect your information against unauthorized access, alteration, disclosure, or destruction. Our security practices include:

• HTTPS encryption: All data transmitted between your browser and our servers is encrypted using SSL/TLS protocols
• Secure webhook endpoints: Form submissions are sent to secure, encrypted endpoints with authentication
• Minimal data collection: We collect only the minimum data necessary to provide our services
• No persistent user accounts: Since we don't require login, there are no user accounts that could be compromised
• Local storage only: Game progress and scores are stored exclusively in your browser, never on our servers
• Regular security audits: We regularly review and update our security practices
• Data anonymization: Where possible, we anonymize and aggregate data to prevent identification of individual users

However, no method of transmission over the Internet or electronic storage is 100% secure. While we strive to use commercially acceptable means to protect your information, we cannot guarantee absolute security. If you have concerns about data security, please contact us immediately.

Data Retention

We retain your information only for as long as necessary to fulfill the purposes outlined in this Privacy Policy, unless a longer retention period is required or permitted by law.

• Feedback and Contact Forms: We retain submitted feedback and contact form data for up to 2 years to improve our services, unless you request earlier deletion
• Analytics Data: Aggregated, anonymized analytics data may be retained indefinitely for statistical purposes, but individual user data is not identifiable
• Game Progress: Stored locally in your browser only. We do not retain this data on our servers. You can delete it at any time by clearing your browser data
• Logs: Server logs containing IP addresses are typically retained for up to 90 days for security and troubleshooting purposes, then automatically deleted

When we no longer need your personal information, we will securely delete or anonymize it. If you request deletion of your data, we will comply within 30 days (or as required by applicable law), except where we are required to retain it for legal purposes.

Your Rights (GDPR/CCPA)

Depending on your location, you may have the following rights regarding your personal information:

• Right to access: You have the right to request access to any personal information we hold about you
• Right to rectification: You can request correction of inaccurate or incomplete information
• Right to erasure: You can request deletion of your personal information (also known as the "right to be forgotten")
• Right to restrict processing: You can request that we limit how we use your information
• Right to data portability: You can request a copy of your data in a structured, machine-readable format
• Right to object: You can object to certain types of processing, including direct marketing
• Right to withdraw consent: If processing is based on consent, you can withdraw it at any time
• Right to lodge a complaint: You have the right to file a complaint with your local data protection authority

To exercise these rights, please contact us using the information provided in the "Contact Us" section below. We will respond to your request within 30 days (or as required by applicable law) and may ask for verification of your identity to protect your privacy.

Note: Since we don't require accounts and store minimal data, most users won't have personal information stored with us. Game progress and scores are stored locally in your browser and can be deleted by clearing your browser data.

Chrome Extension

The DecimalHero Quick Math Chrome extension is a popup practice tool. It does not read the websites you visit, does not require an account, and does not send practice answers or calculator inputs to DecimalHero servers.

• No browsing data: The extension has no host permissions and cannot see page content, tabs you have open, or your history
• Local streak only: An optional practice streak is saved in Chrome local storage on your computer so closing the popup does not reset it
• No analytics in the extension: The extension does not include Google Analytics, advertising, or third-party trackers
• Outbound links: If you click a "more practice" link or use the dh address-bar shortcut, Chrome opens a DecimalHero page. That page follows the rest of this Privacy Policy

You can remove the saved streak by clearing the extension's data in Chrome settings, or by uninstalling the extension.

Children's Privacy

Our Site is designed for educational purposes and is suitable for users of all ages, including students and educators. We take children's privacy seriously and comply with the Children's Online Privacy Protection Act (COPPA) and other applicable laws.

• No account required: Children can use our Site without creating accounts or providing personal information
• No personal data collection: We do not knowingly collect personal information from children under 13
• Parental control: Parents and guardians can monitor their children's use of our Site, and all game progress is stored locally in the browser
• Safe content: Our educational content is appropriate for all ages and focuses solely on math and science education

If you are a parent or guardian and believe your child under 13 has provided us with personal information, please contact us immediately at [email protected] and we will promptly delete such information.

Changes to This Privacy Policy

We may update this Privacy Policy from time to time. We will notify you of any changes by posting the new Privacy Policy on this page and updating the "Last updated" date. You are advised to review this Privacy Policy periodically for any changes.