An ip address has two parts: the address and the netmask.
The address is just a 32-bit binary number. E.g. yours:
However, these addresses are very precise, and without any further information point to exactly one address. But we want to be more general, and be able to talk about a whole group of addresses. That is a block, and what the netmask is for.
When I use a netmask of
/n, it means 'only look at the first n bits of this address, those are meaningful, the rest can be anything'. Think of it like this, the address we give is full, but then we strike out the most specific parts that can be anything:
United States, Middleberge,
Otter Lane 5322
In your case, the first 26 or 25 bits matter, so we strike through the last 6 or 7 bits:
But we still need to combine the blocks. Note that the top two lines have the exact same start, but then one ends in a 0 followed by anything, and the other in a 1 followed by anything. But since that exhaustively covers everything, we can just extend the 'anything' part one up to combine them:
Here we can do the exact same:
We can now convert our IP address back to decimal, giving
18.104.22.168. The netmask is 32 - 8 = 24 (because we strike out 8 binary digits). So the full IP address + netmask is