Learning by Doing: CISCO Certified Network ... - SCN Research

4. Then, with those totals, we use our decimal to hexadecimal conversion chart
above to complete the conversion.
9=9 7=7
The binary octet “11001101” is equivalent to the hexadecimal number “97.”
Don’t think in terms of decimal…this is NOT ninety-seven. In hexadecimal this
is “nine-seven.”
You can convert from decimal to binary and then to hexadecimal. We use subscripts to
denote which base of number we are using (2 for binary, 10 for decimal and 16 for
hexadecimal). Try it with these:
1. 143 10
2. 244 10
3. 78 10
4. 128 10
5. 191 10
Check your answers. Hopefully you are correct! If you have decimal numbers with more
than 255 (our binary octet upper limit) then we have ways to convert them too. To
convert a decimal number to hexadecimal we just keep dividing it by 16 until we get to
zero. The remainders, in reverse order, are used to code the hexadecimal. For example
let’s convert the decimal number 28436 to hexadecimal:
28436 divided by 16 = 1777 R 4
1777 divided by 16 = 111 R 1
111 divided by 16 = 6 R 15
6 divided by 16 = 0 R 6
The remainders, in reverse order, are 6-15-1-4. When we replace 15 with F we get our
hexadecimal conversion of 6F14 (“six-F-one-four”). Ok…So I know a lot of you cheated
and used a calculator. Here is a chart for the remainders converted to whole numbers:
R 0 0/16 0.0000 R 8 8/16 0.5000
R 1 1/16 0.0625 R 9 9/16 0.5625
R 2 2/16 0.1250 R 10 10/16 0.6250
R 3 3/16 0.1875 R 11 11/16 0.6875
R 4 4/16 0.2500 R 12 12/16 0.7500
R 5 5/16 0.3125 R 13 13/16 0.8125
R 6 6/16 0.3750 R 14 14/16 0.8750
R 7 7/16 0.4375 R 15 15/16 0.9375
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