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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 Once a key reasoning benchmark, it is now fully saturated and largely serves as a historical reference point.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

  1. Not supported

    Separates frontier models on mathematical reasoning

    All frontier models score above 95%, leaving no discriminating range.

  2. 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)

  3. 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

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