take the number then divide it by 2 keep dividing the number by 2 untill you get 0 then write the remainders in reverse order
example
we will find the number 12
divide 12 by 2 we get 6 with a remainder of 0
now we divide 6 by 2 we get 3 with a reminder of 0
next we divide 3 by 2 we get 1.5 with a remainder of 1
because we got 1.5 we round down so 1
next we divide 1 by 2 and get -0.5 with a remainder of
1
so the answer is
1100
hope this helps scav