Editorial Policy

Last updated October 3, 2026

How content is made

Each calculator has a formula, a method and worked examples. Guides explain the idea in plain language, work examples through the live calculator, and list the mistakes learners actually make. Every number quoted in a guide is taken from the calculator’s real output, not calculated by hand.

Review

Pages are currently written and checked by the editorial team. We will add a named reviewer to each page only once a real, verifiable person has agreed to be credited — we do not display invented credentials.

Sources

Where a rule or constant comes from an authoritative source, the page cites it. Core arithmetic and algebra need no external source beyond standard textbooks.

Corrections

If you find a mistake, email [email protected]. We fix confirmed errors promptly, add a regression test, and update the “last updated” date on the page.

Independence

We do not publish paid placements, fake testimonials or unsourced ratings.