Ballpark — July 30, 2026
Answers to that day's 5 daily estimation questions.
Total length of the world's coastline
220,000 miles
Difficult to measure exactly due to the coastline paradox.
Hearts in an octopus
3 hearts
Two pump blood to the gills; one to the rest of the body.
Number of moons orbiting Jupiter
115 moons
The four largest (Galilean moons) were seen by Galileo in 1610.
Total diamonds in the UK Crown Jewels
~23,575 diamonds
The Sovereign's Sceptre alone holds the 530-carat Cullinan I.
People who speak English as a first or second language
1.49 billion
Includes native and non-native speakers.