Best AI for everyday maths / head-to-head

GPT-5.6 Luna vs GPT-5.6 Terrafor everyday maths

The verdict

GPT-5.6 Terra wins, 9998

Same 12 everyday maths tasks, marked blind by three rival labs. GPT-5.6 Terra took 1 tasks, GPT-5.6 Luna took 0, 11 tied. Tested 14 Aug 2026.

Where they differed most

The task — Estimate honestly

Roughly how many working hours are there in a UK full-time year? Give your estimate, show the 2-3 assumptions it rests on, and say which assumption moves the answer most.

**Rough estimate: about 1,750 actual working hours per year** for a UK full-time employee.

Assumptions:

1. **37.5 contracted hours per week**.
2. **5.6 weeks’ annual leave**, the UK statutory minimum, including bank holidays.
3. **No substantial sick leave, unpaid leave, or overtime**.

Calculation:

\[
(52 - 5.6)\times 37.5 \approx 1,740\text{ hours}
\]

So a sensible range is **about 1,700–1,850 hours**:

- 37.5 hours/week with typical leave: roughly **1,700–1,750**
- 40 hours/week with statutory leave: roughly **1,856**

The assumption tha…
A reasonable estimate is **about 1,700–1,750 working hours per year** for a UK full-time employee.

Example estimate: **1,740 hours/year**

Assumptions:

1. **37.5 hours per week** (e.g. 9–5 with a 30-minute unpaid lunch)  
   - 37.5 × 52 = **1,950 hours**

2. **28 days’ paid annual leave**, including bank holidays — the UK statutory minimum for a five-day worker  
   - 28 days × 7.5 hours = **210 hours**

3. No allowance for sickness absence, unpaid leave, or other non-working time  
   - 1,950 − 210 = **1,740 hours**

The assumption that move…

Task by task

TaskGPT-5.6 LunaGPT-5.6 Terra
VAT both ways1010
Percentage change vs points1010
Unit price comparison1010
Mortgage overpayment intuition1010
Split a bill with a twist1010
Compound vs simple1010
The discount stack1010
Reverse percentage1010
Rate to reality99
Average of averages trap1010
Estimate honestly910
Refuse false precision1010

Full receipts: GPT-5.6 Luna, GPT-5.6 Terra · judges claude-sonnet-5, gemini-3.1-pro-preview, grok-4.5

Questions people ask

Which is better for everyday maths: GPT-5.6 Luna or GPT-5.6 Terra?

GPT-5.6 Terra — it scored 99/100 against 98/100 on our 12-task everyday maths suite, winning 1 tasks to 0 with 11 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 Terra · Claude Opus 4.8 vs GPT-5.6 Luna · GPT-5.6 Sol vs GPT-5.6 Terra · GPT-5.6 Luna vs GPT-5.6 Sol · Claude Opus 4.6 vs GPT-5.6 Terra · GPT-5.3-Codex vs GPT-5.6 Terra

Full ranking: Best AI for everyday maths · model pages: GPT-5.6 Luna, GPT-5.6 Terra