As people we count in denary which is a number system with a base ten.
Computers count in binary which is a number system with a base two.
Computers use binary to present and manipulate data.
To convert a denary value into binary
Draw a table such as the one below:
If we are converting the number 155
first we minus the largest binary number that goes into 155. In this case we do 155-128 to get 27. In addition we make a note on the table like below:
We find the largest number that 27 can be subtracted by.
We cannot use 64
We cannot use 32
We subtract 27 by 16 to get 11 and make a note on the table:
We then subtract 11 by 8 to get 3 and make a note on the table:
We then find the largest number that 3 can be subtracted by :
We cannot use 8
We cannot use 4
We can subtract 3 by 2 to get 1 and make a note on the table
We then subtract 1 by 1 to get 0 and make a note on the table .
Finally we fill the blanks in with zeros:
155 is equal to 10011011 in binary
To convert binary into denary
We will convert the binary number 01010011
Draw out the table below and fill the binary number
Add the numbers with the values 1 so
01010011 = 83