does anyone know how to convert network addresses into binary digits?

First Question: Which address isn't a valid host address.

This requires knowledge of subnetting. I don't answer homework, but I help with hints. So, my hint is this; The first IP of the network is the network ID and the last is the broadcast address, and neither can be used to address a host. You have the network ID and a subnet mask, so go through the process of subnetting to find out what the range of IP addresses are. I'm not going to explain subnetting here, its a bit long.

Second Question: Decimal to Binary Conversion

This is an important skill and will be needed to answer the first question.

There are a couple ways of converting binary to decimal, but I prefer remember the place values (or order of magnitudes). When you were younger and learning to count, one of the thing you might have been taught was you count up and you get to 9 (in decimal) you start back at 1 with a one in the "ten's place" and a 0 in the "ones place". You keep incrementing until you get to 9 then increment the tens place and so on.

You do the same thing in binary. You start off in 1's place, then 2's, 4's, 8's, 16's, 32's, 64's, and 128's. When you look at the number in binary, you just take all the values that are ones and add them up based on their position. For example, 17 in binary is 00010001, which is (right to left) no 128, no 64, no 32, a 16, no 8, no 4, no 2, and a 1. 16+1=17.

There's also some long division way of converting, which is fine for large numbers, but I found it easier to remember the values of the first 8 positions (as it pertains to IP addresses). Get that down and you will be able to do most conversions in you head, and will make subnetting easier.

Here's a good YouTube video that shows you how to do just that! Subscribe to this channel and you'll find more Network-related info.

HTH

scientific calculator like the HP 35s or hp-50g. 35s is easier to use in general but harder to program. use number bases. binary is base 2. decimal is base 10 (what we normally count with).

Here is a good reference: http://www.cisco.com/web/about/ac123/ac147/archived_issues/ipj_9-1/ip_addresses.html

I'm not sure what you are asking. But here is how you convert a decimal number into binary:

The binary digits are weighted this way:

128 64 32 16 8 4 2 1
0 0 0 1 0 0 0 0 = 16
0 0 0 1 0 0 0 1 = 17
1 0 0 0 0 0 0 0 = 128
1 0 0 0 0 0 0 1 = 129
0 0 0 0 0 1 1 1 = 7
0 0 0 0 1 0 0 0 = 8
0 0 0 0 1 0 0 1 = 9