Calculating IPv6 subnets outside the nibble boundary

Anurag Bhatia
Often this comes into the subnetting discussion by my friends who are deploying IPv6 for the first time. How do you calculate subnets outside the 4-bit nibble boundary? This also happens to be one of starting points of APNIC IPv6 routing workshop where I occasionally instruct as community trainer. So what is a Nibble boundary? In IPv6 context, it refers to 4 bit and any change in multiple of 4 bits is easy to calculate.