Start with 128 then divide by 2 for each value Reverse the order of the Bit Values = Subnets - 2 = Bit Value - 2 = Cumulative Sum of Bit Value = Total Bit Value =24 + Bits Borrowed
Borrowed Bits Bit Value Subnets Usable Subnets Usable Hosts Total Bit Value Subnet Mask Network Bits
1 128 2 0 126 128 255.255.255.128 /25
2 64 4 2 62 192 255.255.255.192 /26
3 32 8 6 30 224 255.255.255.224 /27
4 16 16 14 14 240 255.255.255.240 /28
5 8 32 30 6 248 255.255.255.248 /29
6 4 64 62 2 252 255.255.255.252 /30
7 2 128 126 0 254 255.255.255.254 /31