-955(10) to a signed binary two's complement representation = ?
1. Start with the positive version of the number:
|-955| = 955
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;
- 955 ÷ 2 = 477 + 1;
- 477 ÷ 2 = 238 + 1;
- 238 ÷ 2 = 119 + 0;
- 119 ÷ 2 = 59 + 1;
- 59 ÷ 2 = 29 + 1;
- 29 ÷ 2 = 14 + 1;
- 14 ÷ 2 = 7 + 0;
- 7 ÷ 2 = 3 + 1;
- 3 ÷ 2 = 1 + 1;
- 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.
955(10) = 11 1011 1011(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 10.
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) indicates the sign,
1 = negative, 0 = positive.
The least number that is:
a power of 2
and is larger than the actual length, 10,
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:
955(10) = 0000 0011 1011 1011
6. Get the negative integer number representation. Part 1:
To get the negative integer number representation on 16 bits (2 Bytes),
signed binary one's complement,
replace all the bits on 0 with 1s
and all the bits set on 1 with 0s
(reverse the digits, flip the digits)
!(0000 0011 1011 1011) =
1111 1100 0100 0100
7. Get the negative integer number representation. Part 2:
To get the negative integer number representation on 16 bits (2 Bytes),
signed binary two's complement,
add 1 to the number calculated above
1111 1100 0100 0100 + 1 =
1111 1100 0100 0101
Number -955, a signed integer, converted from decimal system (base 10) to a signed binary two's complement representation:
-955(10) = 1111 1100 0100 0101
Spaces used to group digits: for binary, by 4.
More operations of this kind:
Convert signed integer numbers from the decimal system (base ten) to signed binary two's complement representation