Claude Fable 5.1 · Math
Claude Fable 5.1 for math: our test runs
Claude Fable 5.1 ran our 5 math prompts in llmwise, through the same pipeline your messages take. Here's every reply as it came, whether it passed, what it cost and what it counts as on Pro, next to the other models.
Based on 5 of our test runs on , through OpenRouter with the app's own prompt and settings. Updated .
Short answer
In our test runs on September 27, 2026, Claude Fable 5.1 passed 5 of 5 of our math prompts (both hard ones): tied 1st of 20 models. Each reply counted as 1 message on Pro, where it has 31 a month, and cost $0.0116 to run on average.
Prompt by prompt
Each of the 5 math prompts, and how Claude Fable 5.1's reply did.
| Prompt | Result | Cost | Time |
|---|---|---|---|
| A discount, then sales taxEveryday | Passed: Final answer 66: right. | $0.0086 | 3.6 s |
| Pens at 3 for $4Everyday | Passed: Final answer Buy three 3-for- 4 packs and one single pen, total 13.50: right. | $0.0159 | 5.4 s |
| Compound interest over three yearsEveryday | Passed: Final answer 315.25: right. | $0.0092 | 3.6 s |
| Four-digit numbers whose digits sum to 9Hard | Passed: Final answer 165: right. | $0.0139 | 4.6 s |
| The highest of three dice is a 5Hard | Passed: Final answer 61/216: right. | $0.0106 | 5.9 s |
Every math reply from Claude Fable 5.1
A discount, then sales tax
An everyday prompt: “A discount, then sales tax”, in full.
Passed: Final answer 66: right.
Discounted price: $80 × (1 − 0.25) = $80 × 0.75 = $60 Add 10% tax: $60 × 1.10 = $66 Final answer: $66
543 tokens in, 63 out · 3.6 s · $0.0086 · 1 message on Pro · answered by anthropic/claude-fable-5.1 via Anthropic ·
Pens at 3 for $4
An everyday prompt: “Pens at 3 for $4”, in full.
Passed: Final answer Buy three 3-for- 4 packs and one single pen, total 13.50: right.
Options for 10 pens: - 3 packs of 3 (9 pens) + 1 single: 3 × $4 + $1.50 = $13.50 - 4 packs of 3 (12 pens, but that's more than exactly 10 — not allowed here): $16.00 - 2 packs + 4 singles: $8 + $6 = $14.00 - 1 pack + 7 singles: $4 + $10.50 = $14.50 - 10 singles: $15.00 Cheapest is three 3-packs plus one single pen. Final answer: Buy three 3-for-$4 packs and one single pen, total $13.50
547 tokens in, 208 out · 5.4 s · $0.0159 · 1 message on Pro · answered by anthropic/claude-fable-5.1 via Anthropic ·
Compound interest over three years
An everyday prompt: “Compound interest over three years”, in full.
Passed: Final answer 315.25: right.
Balance after 3 years: 2000 × 1.05³ = 2000 × 1.157625 = $2,315.25 Interest earned: 2,315.25 − 2,000 = $315.25 Final answer: $315.25
541 tokens in, 76 out · 3.6 s · $0.0092 · 1 message on Pro · answered by anthropic/claude-fable-5.1 via Anthropic ·
Four-digit numbers whose digits sum to 9
A hard prompt: “Four-digit numbers whose digits sum to 9”, in full.
Passed: Final answer 165: right.
Let the digits be a, b, c, d with a ≥ 1 (leading digit) and b, c, d ≥ 0, and a + b + c + d = 9. Substitute a' = a − 1 ≥ 0, so a' + b + c + d = 8 with all variables ≥ 0. Number of non-negative integer solutions: C(8 + 3, 3) = C(11, 3) = 165. No digit can exceed 9 since the total is only 9, so no solutions need to be excluded. Final answer: 165
512 tokens in, 175 out · 4.6 s · $0.0139 · 1 message on Pro · answered by anthropic/claude-fable-5.1 via Anthropic ·
The highest of three dice is a 5
A hard prompt: “The highest of three dice is a 5”, in full.
Passed: Final answer 61/216: right.
P(max ≤ 5) = (5/6)³ = 125/216 P(max ≤ 4) = (4/6)³ = 64/216 P(max = 5) = 125/216 − 64/216 = 61/216 61 is prime, so the fraction is already in lowest terms. Final answer: 61/216
539 tokens in, 105 out · 5.9 s · $0.0106 · 1 message on Pro · answered by anthropic/claude-fable-5.1 via Anthropic ·
How it compares on math
Claude Fable 5.1 beside the job's picks among every model. 19 models share the hard-problems pick, Claude Fable 5.1 among them.
| Model | Passed | On Pro | Cost per reply |
|---|---|---|---|
| GLM 5.3Our pick: hard problems (shared), best value | 5 of 5 | 250 a month on Pro | $0.0004 |
| Claude Haiku 5.5Our pick: hard problems (shared), everyday | 5 of 5 | 60 a day on Pro | $0.0001 |
| Claude Fable 5.1Our pick: hard problems (shared) | 5 of 5 | 31 a month on Pro | $0.0116 |
Every limit is published. Paid plans also have a monthly fair-use limit on AI cost: Plus $3.75, Pro $7.50, Max $20, Ultra $42, Studio $85. Using every message on your plan at typical sizes stays under it; very large messages and heavy research use it faster. Every limit, explained.
Claude Fable 5.1 next to each model on math
Claude Fable 5.1 against each model on the same 5 math prompts. One run each, through OpenRouter: a wait depends on the provider and the load that day, so a lead under 10% counts as close.
Against Claude Opus 5.5: Claude Fable 5.1 answered 1.2× later (4.6 s to 3.9 s), cost 2.0× more, and passed 5 of 5 to its 5.
Against Claude Sonnet 5.5: Claude Fable 5.1 answered 2.8× later (4.6 s to 1.7 s), cost 4.7× more, and passed 5 of 5 to its 5.
Against Claude Sonnet 5: Claude Fable 5.1 answered 1.2× later (4.6 s to 3.9 s), cost 3.5× more, and passed 5 of 5 to its 5.
Against Claude Haiku 5.5: Claude Fable 5.1 answered 2.7× later (4.6 s to 1.7 s), cost 79.2× more, and passed 5 of 5 to its 5.
Against Claude Haiku 4.5: Claude Fable 5.1 answered 2.1× later (4.6 s to 2.2 s), cost 7.6× more, and passed 5 of 5 to its 5.
Against GPT-6 Astra: Claude Fable 5.1 answered 1.8× later (4.6 s to 2.6 s), cost 1.4× more, and passed 5 of 5 to its 5.
Against GPT-6.1 Sol: Claude Fable 5.1 answered 2.6× later (4.6 s to 1.8 s), cost 13.5× more, and passed 5 of 5 to its 5.
Against GPT-6 Sol: Claude Fable 5.1 answered 2.1× later (4.6 s to 2.2 s), cost 6.4× more, and passed 5 of 5 to its 5.
Against GPT-6 Luna: Claude Fable 5.1 answered 2.1× later (4.6 s to 2.2 s), cost 118.2× more, and passed 5 of 5 to its 4. Only Claude Fable 5.1 passed Pens at 3 for $4.
Against Gemini 4 Argon: Claude Fable 5.1 answered within 10% of its time (4.6 s to 4.4 s), cost 7.5× more, and passed 5 of 5 to its 5.
Against Gemini 3.1 Pro (preview): Claude Fable 5.1 answered 1.8× sooner (4.6 s to 8.3 s), cost 1.2× more, and passed 5 of 5 to its 5.
Against Gemini 3.8 Flash: Claude Fable 5.1 answered within 10% of its time (4.6 s to 4.7 s), cost 8.2× more, and passed 5 of 5 to its 5.
Against DeepSeek V4.1 Flash: Claude Fable 5.1 answered 5.0× later (4.6 s to 0.9 s), cost 46.5× more, and passed 5 of 5 to its 5.
Against DeepSeek V4 Pro: Claude Fable 5.1 answered 1.7× later (4.6 s to 2.7 s), cost 13.3× more, and passed 5 of 5 to its 5.
Against Grok 4.7: Claude Fable 5.1 answered 2.5× sooner (4.6 s to 11.7 s), cost 1.6× more, and passed 5 of 5 to its 5.
Against Kimi K3: Claude Fable 5.1 answered 1.2× sooner (4.6 s to 5.4 s), cost 3.1× more, and passed 5 of 5 to its 5.
Against GLM 5.3: Claude Fable 5.1 answered 4.9× later (4.6 s to 0.9 s), cost 32.9× more, and passed 5 of 5 to its 5.
Against GLM 5.3 Flash: Claude Fable 5.1 answered 1.7× later (4.6 s to 2.7 s), cost 77.5× more, and passed 5 of 5 to its 5.
Against Mistral Large 4: Claude Fable 5.1 answered within 10% of its time (4.6 s to 5.1 s), cost 6.4× more, and passed 5 of 5 to its 5.
How these runs were done
Final answer. Automatic. The reply's last “Final answer:” line must hold the right value.
Claude Fable 5.1, and math, elsewhere
- Claude Fable 5.1: price, limits and messages on every plan
- The best AI for math: our picks among every model
- Claude Fable 5.1 for coding: our test runs
- Claude Fable 5.1 for writing: our test runs
- Claude Fable 5.1 for data analysis: our test runs
- Claude Fable 5.1 vs GPT-6 Astra
- Claude Fable 5.1 vs Claude Opus 5.5
- Claude Fable 5.1 vs Kimi K3
- Claude Fable 5.1 vs Grok 4.7
- Claude Fable 5.1 vs Claude Sonnet 5
- Claude Fable 5.1 vs Claude Haiku 4.5
- Analyze a CSV with code: the prompt, and its price
- AI prompts for students, tested on four models
- AI prompts for teachers, tested with every reply
- Our test runs: 50 prompts on every model
Questions
Is Claude Fable 5.1 good for math?
In our test runs it passed 5 of 5 math prompts, tied 1st of the 20 models in llmwise. Every reply is on this page, so you can judge them yourself.
How many of my messages does a math reply from Claude Fable 5.1 use?
1 message each on Pro, where it has 31 a month on Pro. The price of a message is fixed and shown before you send it, however long the reply.
How were these runs done?
The same way for every model: each prompt sent through llmwise's own pipeline, each reply checked the same way. The methods page has every prompt and how each is scored.
Claude, GPT, Gemini, DeepSeek, Grok, Kimi, GLM, and Mistral, in one chat.
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