Best AI for everyday maths / head-to-head

Claude Opus 4.8 vs GPT-5.6 Terrafor everyday maths

The verdict

Claude Opus 4.8 wins, 10099

Same 12 everyday maths tasks, marked blind by three rival labs. Claude Opus 4.8 took 1 tasks, GPT-5.6 Terra took 0, 11 tied. Tested 14 Aug 2026.

Where they differed most

The task — Rate to reality

A car does 42 miles per gallon. Petrol is £1.46/litre. One gallon is 4.546 litres. What does a 260-mile journey cost in fuel, to the nearest 10p? Show each step.

# Fuel Cost Calculation

## Step 1: Find gallons needed
$$260 \div 42 = 6.1905 \text{ gallons}$$

## Step 2: Convert gallons to litres
$$6.1905 \times 4.546 = 28.142 \text{ litres}$$

## Step 3: Calculate the cost
$$28.142 \times £1.46 = £41.088$$

## Step 4: Round to the nearest 10p
$$£41.088 \approx £41.10$$

## Answer
**The journey costs approximately £41.10 in fuel.**
1. **Gallons needed for 260 miles:**

\[
\frac{260}{42}=6.1905\text{ gallons}
\]

2. **Convert gallons to litres:**

\[
6.1905 \times 4.546 = 28.1419\text{ litres}
\]

3. **Calculate fuel cost:**

\[
28.1419 \times £1.46 = £41.0872
\]

4. **Round to the nearest 10p:**

\[
£41.0872 \approx £41.10
\]

**The 260-mile journey costs approximately £41.10 in fuel.**

Task by task

TaskClaude Opus 4.8GPT-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 reality109
Average of averages trap1010
Estimate honestly1010
Refuse false precision1010

Full receipts: Claude Opus 4.8, GPT-5.6 Terra · 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-5.6 Terra?

Claude Opus 4.8 — it scored 100/100 against 99/100 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 Sol · 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 · Claude Opus 4.8 vs Grok 4.5

Full ranking: Best AI for everyday maths · model pages: Claude Opus 4.8, GPT-5.6 Terra