yielding networks

I currently have a network adress of
192.168.97.0 /23

i have
34 hosts in room A
34 hosts in room B
70 hosts in room C

currently all of the hosts or on the same network number^
but now i need to find 3 networks and make each room its own network

i was thinking of first yielding the subnet for the given network
and then just filling in the hosts,but it wouldnot work

You could use the following scheme:

Room C: 192.168.96.1 --> 192.168.96.126 /25
Room B: 192.168.96.129 --> 192.168.96.190 /26
Room A: 192.168.96.193 --> 192.168.96.254 /26

Did this in a hurry so please recheck. If you have further questions, don't hesitate to ask.

thanks man I found out this scheme too.

if the bits expand between the host and network portions
you can do 2^n-2
then use n as the number of bits available
and fill in the colums starting at 00 but we omit 00

so
00
01
11
01
..etc