Reasoning · 1 checks · max 800 tokens · benched 2026-09-16
Anthropic models side by side on "Stacked discounts and tax": Claude Sonnet 5 scores 10/10; Claude Sonnet 5 is the cheapest answer scoring 8+ at $0.56 per 1,000 runs. Outputs, checks, judge reasons, latency and cost.
System
Think carefully, then give only the final answer in the requested format.
User
An item costs $250.00. A 20% discount is applied, then a $15.00 coupon is subtracted, and finally 8% sales tax is added to the resulting amount. What is the final price? Reply with only the amount in dollars to two decimal places, for example 12.34, with no currency symbol.
Rubric for the judge: The single correct answer 199.80 (250 x 0.8 = 200; 200 - 15 = 185; 185 x 1.08).
Every cell is one OpenRouter call at temperature 0 with the prompt's token cap and reasoning effort "low" where the model supports it. Cost is usage × the catalogue rate in models.json. Quality is one judge call to anthropic/claude-haiku-4.5 against the prompt's rubric, cached per prompt version.
anthropic/claude-opus-5
121 in · 28 out (23 reasoning) · 1 words · checks 1/1
199.80
Judge: The output matches the correct answer of 199.80 in the exact format requested (two decimal places, no currency symbol).
anthropic/claude-sonnet-5
121 in · 32 out (26 reasoning) · 1 words · checks 1/1
199.80
Judge: The output matches the correct answer of 199.80 in the exact format requested (two decimal places, no currency symbol).
anthropic/claude-sonnet-4.6
95 in · 52 out (44 reasoning) · 1 words · checks 1/1
199.80
Judge: The output matches the correct answer of 199.80 in the exact format requested (two decimal places, no currency symbol).
anthropic/claude-haiku-4.5
94 in · 176 out · 67 words · checks 0/1
Let me work through this step-by-step. Starting price: $250.00 Step 1: Apply 20% discount 20% of $250.00 = 0.20 × $250.00 = $50.00 Price after discount: $250.00 - $50.00 = $200.00 Step 2: Subtract $15.00 coupon Price after coupon: $200.00 - $15.00 = $185.00 Step 3: Add 8% sales tax 8% of $185.00 = 0.08 × $185.00 = $14.80 Final price: $185.00 + $14.80 = $199.80 199.80
Judge: The output correctly calculates the final price as 199.80 through all three steps (discount, coupon, tax) and provides the answer in the exact format requested (bare number to two decimal places with no currency symbol).
Reasoning: The single correct answer 199.80 (250 x 0.8 = 200; 200 - 15 = 185; 185 x 1.08). The deterministic checks are exact.
If the judge's bar of 8/10 is good enough for you, Claude Sonnet 5 at $0.56 per 1,000 runs. If you need the top score, Claude Sonnet 5 at $0.56 per 1,000 runs.
Run it yourself
Re-run this prompt on Anthropic with your own OpenRouter key, or tweak the wording and see what changes.
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