Subnetting Example 8

Convert decimal into binary

Example 8:

We have to find out binary value in given decimal number 180 and tell me which class it comes from ?

Note: You should always follow from left to right

Solution:

It comes from class B value given in above

Base position    2^7  2^6  2^5  2^4  2^3  2^2  2^1  2^0
Decimal value   128   64   32    16     8     4      2      1     
Binary value         1      0     1      1      0     1      0       0


After completing we can check by adding all "1"s given below;

128 + 32 + 16 + 4 = 180 

Rough note:

We can do this adding method given below;

Decimal calculations                                                         Bit in binary
128 is less than 180                                                                on the bit
128 + 64 = 192 is greater than to 180                                     off the bit
128 + 0 + 32 = 160 is less than 180                                        on the bit
128 + 0 + 32 + 16 = 176 is less than 180                                on the bit
128 + 0 + 32 + 16 + 8 = 184 is greater than 180                     off the bit
128 + 0 + 32 + 16 + 0 + 4 = 180 is equivalent to 180              on the bit
128 + 0 + 32 + 16 + 0 + 4 + 2 = 182 is greater than to 180     off the bit
128 + 0 + 32 + 16 + 0 + 4 + 0 + 1 = 181 is greater than 180   off the bit

This is another way of doing through subtracting method which is done in a simple and easy way given below;

Decimal calculation                                                            Bit in binary
180 - 128 = 52 is less than 180                                               on the bit
52 - 64 cannot be subtracted                                                   off the bit
52 - 32 = 20 is less than 180                                                   on the bit
20 - 16 = 4 is less than 180                                                     on the bit
4 - 8 cannot be subtracted                                                       off the bit
4 - 4 = 0 is less than 180                                                         on the bit
0 - 2 cannot be subtracted                                                       off the bit
0 - 1 cannot be subtracted                                                       off the bit


Therefore, this is our binary value 10110100.