Best AI for everyday maths / head-to-head

Claude Opus 4.8 vs Kimi K3for everyday maths

The verdict

Claude Opus 4.8 wins, 10098

Same 12 everyday maths tasks, marked blind by three rival labs. Claude Opus 4.8 took 3 tasks, Kimi K3 took 0, 9 tied. Tested 14 Aug 2026.

Where they differed most

The task — Split a bill with a twist

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**
**Working:**

£187.50 − £12.50 = £175.00 (the amount left for the four to split)

£175.00 ÷ 4 = **£43.75 each**

Task by task

TaskClaude Opus 4.8Kimi K3
VAT both ways1010
Percentage change vs points1010
Unit price comparison1010
Mortgage overpayment intuition1010
Split a bill with a twist109
Compound vs simple1010
The discount stack1010
Reverse percentage1010
Rate to reality1010
Average of averages trap1010
Estimate honestly109
Refuse false precision109

Full receipts: Claude Opus 4.8, Kimi K3 · 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 Kimi K3?

Claude Opus 4.8 — it scored 100/100 against 98/100 on our 12-task everyday maths suite, winning 3 tasks to 0 with 9 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-5.3-Codex · Claude Opus 4.8 vs GPT-5.5 · Claude Opus 4.8 vs GPT-5.6 Luna

Full ranking: Best AI for everyday maths · model pages: Claude Opus 4.8, Kimi K3