# log-keisan.com

> log-keisan.com offers a suite of free, intuitive mathematical tools, including a primary logarithm calculator that provides detailed, step-by-step solutions, designed to assist Japanese high school students, university students, and professionals. The site also features engaging educational games to make learning math fun.

## Core Content
- [Logarithm Calculator (対数計算機)](https://log-keisan.com): An easy-to-use calculator for various logarithm bases (e.g., 10, e, 2). It supports fraction and scientific notation inputs, shows step-by-step solutions, and includes features like copy-to-clipboard and calculation history. It is optimized for mobile use.
- [Math Games (数学ゲーム)](https://log-keisan.com/games): A collection of interactive and educational math games designed to build foundational skills. This section includes the "Prime Factorization Game" (素因数分解ゲーム), which helps users practice breaking down numbers into their prime factors in a fun, timed environment.
- [Math Tools (数学ツール)](https://log-keisan.com/tools): A set of utilities to help visualize and understand mathematical concepts. This includes the "Common Logarithm Grapher," which allows users to see the graph of the common logarithm function and understand its properties.
- [Logarithm Formulas (対数公式)](https://log-keisan.com/formulas): A concise and handy reference page listing essential logarithm identities and formulas that are crucial for students and anyone working with logarithms.
- [Understanding Logarithms (対数ガイド)](https://log-keisan.com/guide): A comprehensive guide for beginners that explains what logarithms are, the different types (common, natural, binary), their basic rules, and how they are used in real life for things like earthquake magnitudes and sound levels.

## Common Resources
- [Privacy Policy (プライバシーポリシー)](https://log-keisan.com/privacy): Details on what user data is collected and how it is used, ensuring transparency with our users.
- [Terms of Service (利用規約)](https://log-keisan.com/terms): The terms and conditions for using log-keisan.com, outlining user responsibilities and site policies.
- [About Us (このサイトについて)](https://log-keisan.com/about): Information about the mission and purpose of log-keisan.com and the value it aims to provide to its users.

## Recent Updates & Key Features
- **Prime Factorization Game Launch**: A new, interactive game at `/games/prime-factorization-game` to help users learn and practice prime factorization with different difficulty levels.
- **Common Logarithm Graphing Tool**: A new visual tool at `/tools/common-log-grapher` for graphing and exploring the properties of common logarithms.
- **Fraction & Scientific Notation Support**: The main calculator now parses and correctly evaluates inputs like "3/8" or "2.3e-5".
- **Auto-Calculation Feature**: The calculator provides real-time results as the user types, improving the user experience.
- **Anti-Log Mode**: A new toggle allows users to switch between logarithm and anti-logarithm (exponential) calculations.