According to http://www.minecraft-crafting.net/, 6 wooden planks and 1 stick gives you 3 signs. but in minecraft pe, when you do that you get only 1 sign
MCPE-1847
Crafting Signs
Resolved
Duplicate
0
Duplicate of MCPE-1218, please use the search function to see if your bug has already been submitted. Currently over 55% of tickets are being closed as duplicate.