How a formula ends up on this site, how it gets tested, and what happens when a reader flags a problem.
Every calculator here is built on a formula someone had to choose and verify: the quadratic formula, the power rule, Heron's formula, and so on. This page explains where those formulas come from, how the arithmetic gets checked before anything ships, and what we do when a reader tells us something looks wrong.
Every formula on MathCalcTools is a standard, named mathematical formula rather than something invented for this site: the quadratic formula for solving ax squared plus bx plus c equals zero, the power rule for basic derivatives, the Pythagorean theorem, and similar textbook methods. Where a formula benefits from a citation beyond "this is standard math," articles link to a reference such as Wolfram MathWorld rather than asserting it without support. Nothing here claims to be original research.
Before a calculator goes live, its logic is checked by hand against known inputs and outputs, the same worked examples that later appear in the site's articles. The square root tool, for instance, is verified against a set of perfect squares and non-perfect squares to confirm the radical simplification and the decimal approximation both come out right. The formulas reference page lists the exact formula behind every calculator, pulled from the same code the live tools run, so the reference and the tools cannot drift out of sync.
A calculator on this site is expected to show its method, not just its answer: the factoring behind a simplified radical, the discriminant before the roots of a quadratic, the rise and run behind a slope. If a tool cannot expose that reasoning in a way a student could follow with a pencil, it does not get published in that form. The articles apply the same standard: every FAQ answer on an article page matches the structured data behind it exactly, and worked examples in the prose are checked against the corresponding calculator before publication.
If you find a wrong formula, a rounding error, or a factual mistake in a guide, send the details through the contact page, including the page and the specific numbers involved. We rebuild the exact scenario by hand before changing any code, so we know whether the issue is the formula, the rounding, or the explanation. Confirmed fixes are made directly on the page in question.
Calculator guides and articles are written by Marcus Vance, a contributing writer covering technology and data for Encore Editorial. Chris Terry owns and operates the site and handles its technical and business side; he does not write or edit the calculator content. See the authors page for both roles in full.