Page one covers the maths questions that come up constantly outside classrooms: what 15% off actually costs, how to add fractions with different denominators, whether a number is prime, and how to move between binary, decimal and hex. Each calculator shows enough working to check homework against, not just a bare answer.
Most percentage confusion is really three different questions: X% of Y, X is what percent of Y, and the percent change from X to Y. The percentage calculator handles all three as explicit modes, which removes the guessing about which formula applies.
The fraction calculator keeps results as exact simplified fractions alongside decimals, and the LCM/GCD tool uses the Euclidean algorithm — the same methods taught in class, so intermediate answers match what students see in textbooks.
Number theory tools — prime factorisation, bases, scientific notation — serve both students and programmers. The base converter covers binary, octal, decimal and hexadecimal in one view, which is the daily bread of anyone reading low-level code or network configs.