Practice Fermi estimation with classic problems like "How many piano tuners in Chicago?" Includes step-by-step reasoning and accepted answers.
Fermi Problem
How many soccer balls would it take to fill this classroom?
Difficulty: Easy
Estimated Answer
~20,000
Reasoning
Classroom ≈ 10m × 8m × 3m = 240 m³. Soccer ball diameter ~22cm, volume ≈ 5,575 cm³. Packing ~64%. 240,000,000 × 0.64 ÷ 5,575 ≈ 27,500. Accounting for furniture: ~20,000.
Accepted Answer
~20,000-25,000
Tip
In Fermi estimation, being within an order of magnitude (10×) is considered a good estimate!