One special characteristic is that 314=159+265 when added mod 10 without carry. Jasper Neumann ------------------------------------- Well, 3 == 1 + 2 1 == 5 + 6 4 == 9 + 5 mod 10. JP ------------------------------------- With the commas placed where they are, the first nine digits are in three groups of three. Let's name these groups A(314), B(159), C(265), from left to right. In all cases, the mod 10 sum of the nth element of B and the nth element of C equals the nth element of A. In Mod 10: first element 3=1+2 second element 1=5+6 third element 4=9+5 Matt Coury ------------------------------- Mathpuzzle.com is awesome and an inspiration. I have discovered so much neat stuff through your website; thanks for all your work. To answer your first poser: 3 = 1 + 2, 1 = 5 + 6, and 4 = 5 + 9 (Mod 10). I’ll have to check to see if there are any similar patterns further on. David Weiss ----------------------------------------- Send an answer to a puzzle in. It’s the Mod one about Pi. 314 159 265. I didn’t see this answer on the answer page so I am sending it to you. 3 - 2 = 1 1 - 6 = 5 4 - 5 = 9 I just found this page like 5 minutes ago. Its pretty cool. Thanks a lot. Nick Mango ---------------------------------------------------