How to convert to binary

1. Convert Denary to Binary (and back again)
Denary: This isthe base 10 system,thismeansthatwe use 10 symbolstorepresentthe numbers(0,1,2, 3, 4, 5,
6, 7, 8, 9) and we use units,tensand hundreds,the number217 can be shownas:
100 10 1
2 1 7
Binary: This isthe base 2 system;there are only2 symbols(0and1):
128 64 32 16 8 4 2 1
1 1 0 1 1 0 0 1
Question: What denary number is shown above in binary (11011001)?
For the GCSE Computing course you need tobe able to:
“Convert positive denary numbers 0 – 255 into 8 bit binary numbers and vice versa”
There are 2 easy methods to convertdenary (base 10 ) to binary (base 2):
Convertbinary (base 2) to denary (base 10):
Put the binarynumberintothe columnsandadd upthe value of the columnswith1 inthem:
128 64 32 16 8 4 2 1
1 1 0 0 1 0 1 0
Gives: 128 + 64 +8 +2
Answer: 202
Use binary columns and take it away
Convertdenary 202 into binary:
202 74 10 2
128 64 32 16 8 4 2 1
1 1 0 0 1 0 1 0
Searchfor the largestbinarycolumnheadingwe
can subtract fromthe number,take itawayand
repeatwiththe remainderuntil we getananswer
of 0
Answer: 11001010