How to convert a signed integer in decimal system (in base 10):
-1 001 016(10)
to a signed binary one's complement representation
1. Start with the positive version of the number:
|-1 001 016| = 1 001 016
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;
- 1 001 016 ÷ 2 = 500 508 + 0;
- 500 508 ÷ 2 = 250 254 + 0;
- 250 254 ÷ 2 = 125 127 + 0;
- 125 127 ÷ 2 = 62 563 + 1;
- 62 563 ÷ 2 = 31 281 + 1;
- 31 281 ÷ 2 = 15 640 + 1;
- 15 640 ÷ 2 = 7 820 + 0;
- 7 820 ÷ 2 = 3 910 + 0;
- 3 910 ÷ 2 = 1 955 + 0;
- 1 955 ÷ 2 = 977 + 1;
- 977 ÷ 2 = 488 + 1;
- 488 ÷ 2 = 244 + 0;
- 244 ÷ 2 = 122 + 0;
- 122 ÷ 2 = 61 + 0;
- 61 ÷ 2 = 30 + 1;
- 30 ÷ 2 = 15 + 0;
- 15 ÷ 2 = 7 + 1;
- 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.
1 001 016(10) = 1111 0100 0110 0011 1000(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 20.
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, 20,
so that the first bit (leftmost) could be zero
(we deal with a positive number at this moment)
is: 32.
5. Positive binary computer representation on 32 bits (4 Bytes):
If needed, add extra 0s in front (to the left) of the base 2 number, up to the required length, 32:
1 001 016(10) = 0000 0000 0000 1111 0100 0110 0011 1000
6. Get the negative integer number representation:
To get the negative integer number representation on 32 bits (4 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 0000 0000 1111 0100 0110 0011 1000) =
1111 1111 1111 0000 1011 1001 1100 0111
Conclusion:
Number -1 001 016, a signed integer, converted from decimal system (base 10) to a signed binary one's complement representation:
-1 001 016(10) = 1111 1111 1111 0000 1011 1001 1100 0111
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 one's complement representation