How many bits are borrowed for the subnet?
Subnets are created in powers of 2 due to the way netmasks
work.
To accomodate 10 addresses, you would need a /28
(255.255.255.240) netmask, which would provide 14 usable IP
addresses. Here are the details of that mask in a private network
address area (192.168.x.x)
Output from the unix "ipcalc" program:
Address: 192.168.1.0 11000000.10101000.00000001.0000 0000
Netmask: 255.255.255.240 = 28 11111111.11111111.11111111.1111
0000
Wildcard: 0.0.0.15 00000000.00000000.00000000.0000 1111
=>
Network: 192.168.1.0/28 11000000.10101000.00000001.0000 0000
HostMin: 192.168.1.1 11000000.10101000.00000001.0000 0001
HostMax: 192.168.1.14 11000000.10101000.00000001.0000 1110
Broadcast: 192.168.1.15 11000000.10101000.00000001.0000 1111
Hosts/Net: 14 Class C, Private Internet
With the /28 netmask, 192.168.1.0 is the network address, and
unusable. 192.168.1.15 is the broadcast address, and is also
non-assignable. This gives 14 usable addresses. A /29 netmask (one
bit less) gives 6 usable addresses.
To create 10 subnets, the size of the subnets would need to be
known, and the process is similar, but the subnets would have
different start and end addresses.