Ballpark — September 30, 2026
Answers to that day's 5 daily estimation questions.
Seconds in a single day
86,400 seconds
24 hours * 60 minutes * 60 seconds.
Weight of a typical bowling ball
12 lbs
Most adults use between 10 and 16 lbs.
Percentage of the world that is water
71%
Most of this is salt water in the oceans.
Monthly active users on Instagram
~3 billion people
A significant jump from its early days in 2010.
Total human population in 1800
~1 billion people
It took all of human history to reach the first billion.