Disclaimer
What this site is, and what it is not.
About the Calculator
It is a learning and convenience tool. Results come from standard JavaScript arithmetic running on your device, and while the functions are tested, no calculator can promise a perfect result for every possible input. Treat an unusual-looking answer as a prompt to check rather than a verdict.
Rounding Is Normal
Computers store most decimals approximately. A long chain of operations can end a fraction of a unit away from the exact value, which is a property of binary floating point rather than a fault in this page. Where a question demands exactness, work in fractions.
Not Professional Advice
Nothing here is financial, legal, medical or engineering advice. A number produced by this page has no professional standing and should never be the only basis for a decision that carries risk.
The Written Guides
The guides explain school-level mathematics in plain language and are deliberately simplified in places. They support a textbook and a teacher; they do not replace either, and they do not follow any single exam board's syllabus.
Outside Links
Links to other sites are for reference. Their content and availability are outside this project's control. Found a mistake here? The contact page explains where to send it.