Reasoning Models
Spending extra think-time on hard problems
Why think longer?
Classic chat answers quickly. Reasoning-style systems allocate more inference-time compute: internal steps before the final answer. That helps multi-step math and logic, but costs latency and tokens. Easy tasks rarely need it.
Lab honesty
Fast vs think modes are a teaching simulator with fixed fixtures, not a live o1/o3-style model. Latency and think-token counts are staged numbers so you can feel the cost dial. Real reasoning models vary by product and hide private scratch pads differently.
Pick a problem
hard
A bat and a ball cost $1.10 in total. The bat costs $1.00 more than the ball. How much does the ball cost?
Cost tradeoff for this problem
Fast
8 tok · 180 ms
Fails this hard item
Think
180 tok · 1240 ms
Shows steps · solves hard fixtures
Extra spend
+172 tok · +1060 ms
Key Insight
Inference-time compute is a dial: more thinking improves hard multi-step work and burns budget. Prefer fast paths for classification and short rewrites; reserve think modes when wrong answers are expensive.
Check your understanding
1/4What is inference-time compute?
Sources, scope & review statusVerified Jul 29, 2026
Claims this lesson makes
- Stable conceptSome systems trade additional inference-time computation for improved performance on selected difficult tasks.
Primary reading
Next content review: 2027-07-29. Source links establish the lesson's claims; interactive numbers remain labeled simulations unless explicitly identified as measured data.