Ballpark — July 13, 2026

Answers to that day's 5 daily estimation questions.

GDP of Bangladesh

460 USD (billions)

One of the fastest-growing economies in South Asia.

Number of teeth in a standard adult mouth

32 teeth

This includes the four wisdom teeth.

Average hours a lightbulb lasted in the 1920s

~2,500 hours

The Phoebus Cartel later limited lifespans to 1,000 hours.

Weight of a typical bowling ball

12 lbs

Most adults use between 10 and 16 lbs.

Cells in the human body

37 trillion

Recent estimates suggest roughly 37 trillion human cells.