Some of the Sudokus were classics: In a 9-by-9 grid, insert a number ... Elis, 16, and Iiris, 11 — joined him on the trip. Tiit Vunk, center, of Estonia, during the Sudoku team competition.

That is a ridiculously large number. Most numbers you're likely to see in your day-to-day life don't need seven commas to be written out. Here's how you get to that astronomical sum. A Sudoku ...