Is your answer right? Check instantly.

Is my math answer right?

Short answer: you can check most answers yourself in under a minute — substitute the answer back into the original equation and see whether both sides balance, then sanity-check the magnitude and the units. When substitution is impractical (proofs, integrals, word problems), photograph the problem together with your answer and get it verified. First 20 checks are free, no account needed.

"Is this right?" is a smaller question than "how do I do this", and it deserves a smaller tool. You do not need a full worked solution — you need a yes or a no, and if it is a no, the line where it went wrong.

Check it yourself first: three methods that need no tool

1. Substitute back. For any equation, put your answer in place of the variable and evaluate both sides. If they match, the answer satisfies the equation. This is a genuine proof for equations, not a heuristic — and it catches nearly every algebra slip.
2. Estimate before you trust. Round everything hard and redo the problem in your head. If your exact answer is 4.7 and the estimate says "about 500", you have a decimal or a unit problem, not a rounding problem.
3. Differentiate an integral, expand a factorisation. Many operations have an inverse that is easier than the original. Factored x² − 5x + 6 into (x−2)(x−3)? Multiply it back out. Integrated something? Differentiate the result and see if you land where you started.

The full set of self-checks, including what to do when there is no answer key at all, is in how to check math answers without an answer key.

When self-checking doesn't work

Substitution has real limits. It cannot help you with:

• Proofs — there is no value to substitute; validity is the whole question.
• "Show your work" problems — a right answer off invalid steps still loses the marks.
• Word problems — substitution verifies your equation, not whether your equation matched the story.
• Problems where you're unsure of the method — you cannot check reasoning you do not trust.

That is where a checker earns its place: it reads what you actually wrote and tells you which line stopped following from the one above it.

Answer form counts too

A mathematically correct answer in the wrong form is still marked wrong. The usual traps: a decimal where an exact radical was asked for, an unsimplified fraction, a missing ±on a square root, a domain restriction dropped after cancelling, a missing unit, or an answer outside the interval the question specified. The check covers form as well as value.

One answer, or the whole page

For a single answer, capture the problem and your result together — the verdict comes back with the reason. For a full problem set, the homework checker flow is a better fit, and the math checker page covers the step-level method in full. Work is handwritten? See solving handwritten math from a photo for photo technique.