Ballpark — April 7, 2026
Answers to that day's 5 daily estimation questions.
Total length of DNA in a human body
~10 billion miles
If you uncoiled all DNA from every cell and laid it end-to-end.
Species of birds in the world
10,000 species
Estimated by the Cornell Lab of Ornithology.
Heart rate of a blue whale
8 beats per minute
Can drop as low as 2 BPM during deep dives.
Petals on a standard sunflower
55 petals
Varies by size and variety.
Total US dollar bills in circulation
54 billion bills
Includes all denominations from $1 to $100.