numbers runners...

how many numbers can be expressed with 32 bits?

4,294,967,296
how many bits in an ipv4 address?
32
how many usable values are available for hosts on the ipv4 internet?
half a billion of those are unusable which leaves about 3.7 billion available
how many ospf areas can there be?

r2620_01(config-router)#netw 10.0.0.0 0.0.0.0 area ?
  <0-4294967295>  OSPF area ID as a decimal value
  A.B.C.D         OSPF area ID in IP address format

how many process id's are available to ospf?
r2620_01(config)#router ospf ?
  <1-65535>  Process ID

what is the default priority value on a switch (bridge) for spanning-tree?
32768

what is 2 to the 15th?
what is 2 times 32768
isn't it nice that 2 to the tenth is 1024
my first computer had 512k ram
how many hosts are available with a slash 23
2 to the fifth is 32
256 divided by 64 is 4, 2 to the second is 4
4 goes into16  4 times and into 32 8 times
32 is half of 64
2 to the 3rd is 8 which goes into 64 8 times
2 to the 7th is 128 which is half of 256
128 plus 64 is 192
256 minus 16 is 240 which equals slash 20 in a B network and slash 28 in a C