Ballpark — June 21, 2026

Number of cards in a standard deck

54 cards

Playing cards originated in China before moving to Europe.

Species of birds in the world

10,000 species

Estimated by the Cornell Lab of Ornithology.

Bones in an adult human body

206 bones

Many bones fuse together as we grow.

Volume of water in the Great Lakes

22,000 cubic km

Enough to flood the continental US 9 feet deep.

Length of an Olympic swimming lap

50 meters

A "lap" usually refers to one length.