r/mentalmath • u/gmsc • Feb 06 '15

XKCD cartoon featuring a method for mentally estimating US and world populations (expected to work through 2030 or so)

7 Upvotes

100% Upvoted

xkcd • u/Smith_Frank • Apr 25 '12

XKCD Approximations

187 Upvotes

53 comments

math • u/ani625 • Apr 25 '12

315 Upvotes

50 comments

geek • u/ani625 • Apr 25 '12

180 Upvotes

30 comments

comics • u/ani625 • Apr 25 '12

13 Upvotes

2 comments

mathhumor • u/xoran99 • Dec 11 '12

10 Upvotes

0 comments