About mathplum

mathplum exists to answer one question well: what is this math, and why? Students searching 7/8 or point slope form do not need a wall of ads and a calculator behind a sign-up. They need the answer, the steps, and a way to practice.

Every number on this site is computed by an exact rational arithmetic engine — integer-based fraction arithmetic, never floating-point rounding. The same engine that writes the answer on the lesson pages grades the printable worksheets, so the two can never disagree.

The site is built and maintained by Nan Liang. You can find more about the author at javaeye.dev/about. Questions, corrections and ideas are welcome at support@mathplum.com — a wrong number anywhere on this site is treated as a bug and fixed at the source.

What mathplum is

• Free step-by-step answers for fractions, expressions and core algebra concepts.
• A worksheet generator that prints a fresh problem set and a separate answer key.
• No accounts, no subscriptions, no paywall, no tracking-heavy third-party scripts.

Editorial standard

Explanations are written for students and parents, then independently double-checked before publishing. Worked examples are solved by the same engine that powers the answer keys, and the factorizations, decimal expansions and percentages you see are generated, not typed.