Reasoning · Evaluator card
GSM8K
2021Karl Cobbe et al. (OpenAI)Paper (opens in a new tab)
Grade School Math 8K is a dataset of 8,792 grade-school-level math word problems requiring multi-step arithmetic reasoning. Once a key reasoning benchmark, it is now fully saturated and largely serves as a historical reference point.
Evidence notes pending review. The verdicts on this card are drafts derived from the benchmark's documentation and published sources; no reviewer has checked them against those sources yet.
Headline claim
GSM8K accuracy supports a smoke test that small or fine-tuned models can solve two- to eight-step grade-school arithmetic word problems; it supports no claim about the mathematical reasoning of current frontier models.
At a glance
- Mechanism
- Deterministic checkerPrior: execution feedback, rung 2 of 4
- Item format
- Short answer
- Size
- 8,792 problems (1,319 test)
- Typical uses
- Measure, Optimize
- Saturation
- Saturated
- Contamination
- High risk
- Year
- 2021
1Claim
What property are we trying to infer, over what world, and for what decision?
- Construct
- Multi-step arithmetic reasoning on natural-language word problems
- Population
- Linguistically diverse grade-school word problems needing 2–8 steps of elementary calculation; the 1,319-problem test split
- Measures
- Basic multi-step arithmetic reasoning with natural language word problems
- Ability to translate simple story problems into a sequence of calculations
- Consistency of getting correct final numerical answers through chain-of-thought reasoning
- Does not measure
- Mathematical reasoning beyond elementary arithmetic — no algebra, geometry, or higher math
- Genuine problem-solving ability, as the problems follow highly predictable templates
- Robustness to problem variation — models that score 95%+ can fail on trivially rephrased versions
- Anything about a model's capability that is still informative, given full saturation by frontier models
2Instrument
How is the judgment actually produced?
- Mechanism
Deterministic checker
Rule-based extraction of the final numeric answer (after an answer marker, or the last number in the output), normalization, and exact match against the reference.
Hierarchy prior: execution feedback, rung 2 of 4. A prior over expected grounding, not a verdict on validity: the evidence notes under Validation say what has been measured.
- Item format
- Short answer
- Specification
- A problem is solved when the final number extracted from the model's (usually chain-of-thought) response equals the reference answer.
- Anchor
- Reference final answer from a human-written solution
- Evidence view
- The final number extracted from the response; intermediate reasoning is not checked
- Signal
- Binary correct/incorrect per problem
- Resolution
- Final answer per problem
- Aggregation
- Accuracy over the test split
- Metrics
- accuracy
- Size
- 8,792 problems (1,319 test)
- Methodology
- Contains 8,792 linguistically diverse grade-school math problems (7,473 train, 1,319 test) that require 2 to 8 steps of elementary calculation. Models generate chain-of-thought solutions and the final numerical answer is extracted and compared to the gold answer. Evaluation is exact-match accuracy on the final number.
3Regime
What causal role does the signal play, and what happens when a system adapts to it?
- Typical uses
- Measure · supports inference and decision
- Optimize · shapes the candidate or policy distribution
- Exposure
- Public train and test splits since 2021. The training split and close variants of the test problems are standard fine-tuning and reinforcement-learning data for reasoning, so the test set has been under direct optimization pressure for years, and contamination across major model families is documented. It was also part of the Hugging Face Open LLM Leaderboard (v1).
- Notes
- Used as a training reward, the final-answer check rewards any route to the right number, including flawed reasoning; it carries no information about the solution steps.
4ValidationDraft
Why should we believe that the signal means what we claim it means — before and after the system adapts to it?
GSM8K's evidence once supported claims about multi-step arithmetic reasoning, but saturation, documented contamination, and a grade-school difficulty ceiling mean it no longer supports claims about modern models' reasoning. Models scoring above 95% can fail on slightly modified versions of the same problems, which shows the score does not hold up under construct-irrelevant changes; MATH or competition-level benchmarks support stronger claims.
Evidence notes1 partially supported · 1 contested · 1 not supported
- Not supported
Separates frontier models on mathematical reasoning
All frontier models score above 95%, leaving no discriminating range.
- Contested
Accuracy reflects reasoning rather than familiarity with the test problems
On freshly written look-alike problems (GSM1k), some model families scored markedly lower while frontier models showed little drop; templated variants that change names and numbers or add an irrelevant clause (GSM-Symbolic) lowered and destabilized accuracy for many models.
Sources: Zhang et al., 2024 (GSM1k); Mirzadeh et al., 2024 (GSM-Symbolic)
- Partially supported
A correct final number implies a correct solution
The checker sees only the final number: a sound method with one arithmetic slip scores zero, and a flawed method that lands on the right number gets full credit.
5Lifecycle
Does the validity survive over time, and are we still evaluating the right thing?
- Saturation
- Saturated
Whether top systems still differ, or crowd the ceiling.
- Contamination
- High risk
How likely test items, or close variants, have leaked into training data.
- Successors
- Last reviewed
- Not yet reviewed · card updated October 12, 2026
Limitations
- Completely saturated — all frontier models score above 95%, eliminating discriminative value
- Extensive contamination documented, with training data overlap across major model families
- Problem templates are predictable enough that models may be pattern-matching rather than reasoning
- Grade-school difficulty ceiling makes it irrelevant for evaluating advanced mathematical ability
- Exact-match evaluation means correct reasoning with minor calculation errors scores the same as random guessing
When to use
- Smoke-testing basic arithmetic reasoning in small or fine-tuned models
- Historical comparison with older systems where GSM8K was the standard reasoning reference
When not to use
- Evaluating mathematical reasoning in any model released after 2023
- Making claims about a model's reasoning or problem-solving capabilities
- Differentiating between frontier models on mathematical tasks
Related benchmarks
- MATHReasoning · 2021A dataset of 12,500 competition-level mathematics problems spanning seven subjects from prealgebra to number theory. It remains more discriminating than GSM8K but is approaching saturation for the strongest frontier models.
- BBHReasoning · 2022BIG-Bench Hard is a curated subset of 23 tasks from the BIG-Bench suite where language models initially performed below average human raters. It tests diverse reasoning skills including logical deduction, causal reasoning, and algorithmic thinking.
Handbook case studies
- A: Mathematical reasoningAnswer checkers, proof assistants, PRMs and mathematicians: one construct, four mechanisms, three regimes, and why a PRM is not "above" the checker.
- E: Reasoning-model trainingDense RLVR and process feedback for development, an untouched certification channel, and judge error re-estimated at every checkpoint.