Maths SolverStep-by-step maths, written by people who teach it.
We publish long-form guides on the high-school and first-year university topics that students actually get stuck on — quadratics, derivatives, the Pythagorean theorem — and pair each one with a small calculator that shows every step of the work, never just the final answer.
Featured guides
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Quadratic equations: from intuition to the formula
Why the discriminant tells you the number of roots before you ever apply the formula, three ways to solve
x² − 5x + 6 = 0by hand, and the mistakes I see most often when students use the formula on a test. -
Derivatives, properly explained
What the derivative actually measures (and what it doesn’t), how the power, product, quotient and chain rules drop out of the limit definition, and how to recognise which one to use without guessing.
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The Pythagorean theorem, four different proofs
A diagram-driven walk through the most famous identity in geometry, with a visual rearrangement proof, an algebraic proof, a similar-triangle proof, and the converse you need for SAT and GCSE problems.
From the blog
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What a proof actually is, and why mathematicians won’t let it go
A proof is not a “convincing argument.” It is the difference between believing something and knowing it. A worked example, three styles of proof, and why even non-mathematicians benefit from learning to write one.
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How SAT Math scoring actually works on the digital test
The two-module adaptive structure, what your score on Module 1 does to Module 2, and why the “raw to scaled” conversion is more interesting than the College Board lets on.
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The week before a maths exam: what I would and would not do
The case against last-minute revision, what to actually do with the seven days, and the morning-of routine I have given to every Year 11 I have ever taught.
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Simple vs compound interest, and why the difference is bigger than you think
Linear growth vs exponential growth, with a year-by-year table for $1000 at 5% over thirty years. The number that comes out at the end is genuinely surprising.
Browse by topic
Most of these sections are still being rewritten. The three guides above are the first finished pieces in the new format — the rest will follow as we have time to do them properly.
Who writes this
Maths Solver is run by two former classroom teachers, Daniel Whitman and Sara Lin. We started the site after years of writing the same explanations on whiteboards for one student at a time, and eventually deciding the explanations might be more useful as something we could actually link to. Everything is free; the site is supported by unobtrusive display ads. There is no app, no premium tier, and no login. You can read more about the project here or get in touch if you spot a mistake.