Best AI for everyday maths / head-to-head
Claude Opus 4.8 vs GPT-5.3-Codexfor everyday maths
Claude Opus 4.8 wins, 100–98
Same 12 everyday maths tasks, marked blind by three rival labs. Claude Opus 4.8 took 2 tasks, GPT-5.3-Codex took 0, 10 tied. Tested 14 Aug 2026.
Where they differed most
Dinner cost £187.50 for 5 people, but one person only had a £12.50 main and drinks no alcohol; the other four agree to split the rest equally. What does each of the four pay? Show the working in two lines.
**Line 1:** Remaining amount = £187.50 − £12.50 = £175.00 **Line 2:** Each of the four pays = £175.00 ÷ 4 = **£43.75**
\[ £187.50 - £12.50 = £175.00 \] \[ £175.00 \div 4 = £43.75 \] So each of the four pays **£43.75**.
Task by task
| Task | Claude Opus 4.8 | GPT-5.3-Codex |
|---|---|---|
| VAT both ways | 10 | 10 |
| Percentage change vs points | 10 | 10 |
| Unit price comparison | 10 | 10 |
| Mortgage overpayment intuition | 10 | 10 |
| Split a bill with a twist | 10 | 9 |
| Compound vs simple | 10 | 10 |
| The discount stack | 10 | 10 |
| Reverse percentage | 10 | 10 |
| Rate to reality | 10 | 10 |
| Average of averages trap | 10 | 10 |
| Estimate honestly | 10 | 9 |
| Refuse false precision | 10 | 10 |
Full receipts: Claude Opus 4.8, GPT-5.3-Codex · judges gemini-3.1-pro-preview, gpt-5.6-terra, grok-4.5
Questions people ask
Which is better for everyday maths: Claude Opus 4.8 or GPT-5.3-Codex?
Claude Opus 4.8 — it scored 100/100 against 98/100 on our 12-task everyday maths suite, winning 2 tasks to 0 with 10 tied. Every answer was marked blind by three judges from three rival AI labs.
How was this tested?
Both models answered the identical published everyday maths tasks. Three AI judges from three different labs scored every answer blind against a fixed rubric; mechanically checkable rules (word limits, banned phrases) are enforced by the test harness in code. The raw outputs and judge verdicts are downloadable.
More everyday maths head-to-heads: Claude Opus 4.8 vs GPT-5.6 Sol · Claude Opus 4.8 vs GPT-5.6 Terra · Claude Opus 4.6 vs Claude Opus 4.8 · Claude Opus 4.8 vs GPT-5.5 · Claude Opus 4.8 vs GPT-5.6 Luna · Claude Opus 4.8 vs Grok 4.5
Full ranking: Best AI for everyday maths · model pages: Claude Opus 4.8, GPT-5.3-Codex