Choose your challenge level from Easy to Hard, select the operations you want to practice, set your pace with a customizable timer, and dive into focused sessions designed to improve speed and accuracy. After each session, review your mistakes in the Wrong Book, track your progress with detailed statistics, and watch your skills grow over time. Key Features: - Customizable Practice: Select difficulty, operations, number of questions, and time limit to match your skill level. - Wrong Book: Automatically saves missed problems so you can review and learn from mistakes. - Progress Statistics: Visual stats including accuracy rate, best score, total sessions, and average time per session. - Clean & Focused Design: Minimalist interface keeps you focused on solving problems without distractions. - Sound & Vibration Feedback: Optional audio and haptic feedback to enhance the practice experience. - Completely Offline: No internet required. All data stays safely on your device.