How to convert the signed integer in decimal system (in base 10):
-2 655(10)
to a signed binary
1. Start with the positive version of the number:
|-2 655| = 2 655
2. Divide the number repeatedly by 2:
Keep track of each remainder.
We stop when we get a quotient that is equal to zero.
- division = quotient + remainder;
- 2 655 ÷ 2 = 1 327 + 1;
- 1 327 ÷ 2 = 663 + 1;
- 663 ÷ 2 = 331 + 1;
- 331 ÷ 2 = 165 + 1;
- 165 ÷ 2 = 82 + 1;
- 82 ÷ 2 = 41 + 0;
- 41 ÷ 2 = 20 + 1;
- 20 ÷ 2 = 10 + 0;
- 10 ÷ 2 = 5 + 0;
- 5 ÷ 2 = 2 + 1;
- 2 ÷ 2 = 1 + 0;
- 1 ÷ 2 = 0 + 1;
3. Construct the base 2 representation of the positive number:
Take all the remainders starting from the bottom of the list constructed above.
2 655(10) = 1010 0101 1111(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 12.
A signed binary's bit length must be equal to a power of 2, as of:
21 = 2; 22 = 4; 23 = 8; 24 = 16; 25 = 32; 26 = 64; ...
First bit (the leftmost) is reserved for the sign:
0 = positive integer number, 1 = negative integer number
The least number that is:
a power of 2
and is larger than the actual length, 12,
so that the first bit (leftmost) could be zero
(we deal with a positive number at this moment)
is: 16.
5. Positive binary computer representation on 16 bits (2 Bytes):
If needed, add extra 0s in front (to the left) of the base 2 number, up to the required length, 16:
2 655(10) = 0000 1010 0101 1111
6. Get the negative integer number representation:
To get the negative integer number representation on 16 bits (2 Bytes),
change the first bit (the leftmost), from 0 to 1:
-2 655(10) =
1000 1010 0101 1111
Conclusion:
Number -2 655, a signed integer, converted from decimal system (base 10) to signed binary:
-2 655(10) = 1000 1010 0101 1111
First bit (the leftmost) is reserved for the sign:
0 = positive integer number, 1 = negative integer number
Spaces used to group digits: for binary, by 4; for decimal, by 3.
More operations of this kind:
Convert signed integer numbers from the decimal system (base ten) to signed binary