Learn the of U.S. presidents by dragging cards to correct sequence. View portraits, names, political parties, and years in office. Test knowledge with interactive quizzes and progress tracking.
Convert numbers between decimal, binary, hexadecimal,
Convert numbers between decimal, binary, hexadecimal, and octal systems. Input integers from 0 to 2^31-1. Perform conversions in both directions. Display results in selected number formats.
Look up Cantonese characters and their Pinyin pronunciations. Support traditional and simplified Chinese characters. Search by character or pronunciation. Listen to audio pronunciations. Bookmark search results for later reference.
