Claude Haiku 4.5 vs R1 for Math

What Math demands: precise symbolic and numerical reasoning, reliable step-by-step derivations, strict structured outputs for formulas or proofs, and the ability to hold long multi-step contexts. External benchmark priority: on MATH Level 5 (Epoch AI) — the direct measure for high-difficulty math — R1 scores 93.1% (Epoch AI); Claude Haiku 4.5 has no Epoch AI MATH Level 5 score, creating a gap in third-party evidence. Internal signals that matter and how each model performs in our tests: - Strategic analysis: tied at 5/5 (both models handle nuanced tradeoffs). - Creative problem solving: R1 5 vs Haiku 4 (R1 generates more novel, feasible math strategies in our tests). - Structured output: tie 4/5 (both formats adhere to schemas). - Tool calling: Haiku 4.5 scores 5 vs R1 4 (Haiku is better at selecting and sequencing functions in our tool-calling tests). - Long context: Haiku 5 vs R1 4 (Haiku holds longer derivations more reliably). - Faithfulness: both 5 (stick to source material and avoid hallucination). Because Epoch AI’s MATH Level 5 is the primary metric for mathematical correctness and difficulty, we prioritize R1’s 93.1% external score above internal proxies when declaring the winner.

Where R1 shines (use R1): - Contest prep and competition problems: R1’s 93.1% on MATH Level 5 (Epoch AI) indicates strong correctness on high-difficulty problems (ideal for AIME/IMO-style practice). - Complex strategy + creativity: internal creative_problem_solving 5 and strategic_analysis 5 mean R1 generates novel solution approaches and correct stepwise plans in our tests. - Cost-sensitive large runs: R1 output cost $2.50 per mTok vs Claude Haiku 4.5 at $5.00 per mTok, so R1 gives higher external math accuracy at lower output cost. Where Claude Haiku 4.5 shines (use Haiku 4.5): - Long derivations or multi-part notebooks: Haiku’s long_context 5 and max context 200,000 tokens help when you need to keep extensive working notes or exam transcripts in a single session. - Tool-driven numeric precision: Haiku’s tool_calling 5 (vs R1’s 4) suggests it selects and sequences computation tools more accurately in our tool tests — useful if you plan to call exact calculators or CAS tools. - Safer routing and classification tasks around math content: Haiku’s classification 4 vs R1’s 2 and safety_calibration 2 vs 1 indicate better behavior for mixed math+policy workflows. Concrete grounded comparisons from our data: - External: R1 93.1% on MATH Level 5 (Epoch AI); Haiku has no external score to compare. - Internal proxies relevant to math: creative_problem_solving 5 (R1) vs 4 (Haiku); structured_output 4 vs 4 (tie); tool_calling 5 (Haiku) vs 4 (R1).

For Math, choose R1 if you need contest-level accuracy and third-party validation — R1 scores 93.1% on MATH Level 5 (Epoch AI), ranks 7 of 52 on our Math task, and has stronger creative problem-solving signals. Choose Claude Haiku 4.5 if your workflow requires very long contexts, heavier tool-calling/automation inside sessions, or better classification/safety calibration in mixed workflows — but note Haiku has no external MATH Level 5 score in Epoch AI and its output cost is $5.00 per mTok vs R1’s $2.50.