Algebra Substitution Question Generator
Builds a sheet of substitution questions at the level you ask for. Every expression evaluates to a whole number, including the ones that divide, so a wrong answer is a mistake in the working rather than in the rounding. Every question is computed and checked directly — not a fabricated or AI-guessed fact.
What this generator does
Generates substitution questions with answers — evaluate an expression for given values. Substitution is worth isolating from solving, because it is where sign errors and missing brackets appear, and both are invisible until the arithmetic goes wrong.
How to use this tool
- Choose a level and how many questions you want.
- Press make questions and work through the sheet.
- Show the answers to mark it, or show the working to see which part of the expression is worked out first.
- Enter a seed word to rebuild the same sheet later.
Common use cases
- Algebra substitution practice
- Quick maths warm-ups
- Self-testing before a maths quiz
Randomness and fairness
Both the expression's coefficients and the substituted values are drawn with the browser's cryptographic random number generator, and the answer is computed exactly. Negative values appear regularly rather than occasionally, since those are the ones that expose the bracket problem. A seed word rebuilds the same sheet later; it is for reproducibility, not cryptographic strength, so a seeded sheet is deterministic rather than unpredictable.
For how randomness is produced across the whole site, see how Generate Random works.
Common mistakes
- Substituting a negative without brackets
- If x = −3 then x² is (−3)², which is 9. Writing −3² gives −9, which is a different expression.
- Reading 3x as thirty-something
- 3x with x = 4 is 12, not 34. The missing sign is multiplication.
Related generators
- Simple Equation GeneratorLinear equations built to order — one step, two steps, unknowns on both sides and brackets — each with a whole-number solution.
- Expanding Brackets Question GeneratorProducts of two linear brackets to multiply out, with each of the four partial products written separately.
- Logic Simplification Challenge GeneratorDeliberately over-complicated expressions built by applying an identity backwards, with the law named and equivalence proved on every assignment.
- Eigenvalue Practice GeneratorMatrices with whole-number eigenvalues, built by conjugating a triangular matrix, with trace and determinant as the check.
- Order of Operations Question GeneratorBODMAS/PEMDAS questions built so the order genuinely changes the answer, with worked steps.
- Index Laws Question GeneratorSimplification questions on multiplying and dividing powers, in one letter or two, with the numbers and the indices handled separately.