Ballpark — September 1, 2026
Answers to that day's 5 daily estimation questions.
Years the Roman Empire lasted
1,000 years
The western empire fell in 476 AD.
Length of the Great Wall (all sections)
13,000 miles
The wall was built over many centuries by various dynasties.
Size of the Sahara Desert
3.6 million square miles
It covers nearly one-third of the African continent.
Depth of the Mariana Trench
36,000 feet
The Challenger Deep is the deepest known point.
Length of the Amazon River
4,000 miles
It carries more water than any other river system.