Privacy notice
Prepared September 22, 2026. This notice is for the redesigned Korean and English site. This notice applies to the published Korean and English website.
Using worksheets
The redesigned version does not require an account or student information. Problem generation and print preparation take place in the browser. A shared set URL may include numbers and options needed to recreate practice. Do not add personal information to a shared URL.
Contact ohy0973@gmail.com. Your email address, message and attachments are used to answer questions and investigate errors. Email is delivered and stored through Gmail. Do not send a child’s name, school or photograph. Send requests to correct or delete a message to the same address. Messages are retained while needed to respond and investigate follow-up errors, and deleted when that purpose ends or a deletion request is verified, subject to any legal retention obligation.
Connection information
The current domain points to GitHub Pages. GitHub may process IP addresses, requested URLs, request times and browser information to deliver and secure pages and investigate faults. See the GitHub Privacy Statement for its processing and retention practices. The site operator does not set GitHub’s access-log retention period. See Google’s Privacy Policy for the email service.
Advertising and cookies
No advertising or separate visitor analytics code is connected to this website. The US site plans to use Google AdSense only. Additional advertising providers for the Korean site have not been selected; no data is sent to unselected providers by this version. Before introducing Google AdSense, we will update this notice for the actual use of cookies, web beacons, IP addresses and identifiers by Google and advertising partners, and implement the required consent choices. Read how Google uses information from partner sites and visit Google ad settings.
Updates
Changes to services or information handling will be reflected here with an updated date. This notice describes the services currently included on this website.