Convert -1 585 743 880 to a Signed Binary in Two's (2's) Complement Representation
How to convert decimal number -1 585 743 880(10) to a signed binary in two's (2's) complement representation
What are the steps to convert decimal number
-1 585 743 880 to a signed binary in two's (2's) complement representation?
- A signed integer, written in base ten, or a decimal system number, is a number written using the digits 0 through 9 and the sign, which can be positive (+) or negative (-). If positive, the sign is usually not written. A number written in base two, or binary, is a number written using only the digits 0 and 1.
1. Start with the positive version of the number:
|-1 585 743 880| = 1 585 743 880
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;
- 1 585 743 880 ÷ 2 = 792 871 940 + 0;
- 792 871 940 ÷ 2 = 396 435 970 + 0;
- 396 435 970 ÷ 2 = 198 217 985 + 0;
- 198 217 985 ÷ 2 = 99 108 992 + 1;
- 99 108 992 ÷ 2 = 49 554 496 + 0;
- 49 554 496 ÷ 2 = 24 777 248 + 0;
- 24 777 248 ÷ 2 = 12 388 624 + 0;
- 12 388 624 ÷ 2 = 6 194 312 + 0;
- 6 194 312 ÷ 2 = 3 097 156 + 0;
- 3 097 156 ÷ 2 = 1 548 578 + 0;
- 1 548 578 ÷ 2 = 774 289 + 0;
- 774 289 ÷ 2 = 387 144 + 1;
- 387 144 ÷ 2 = 193 572 + 0;
- 193 572 ÷ 2 = 96 786 + 0;
- 96 786 ÷ 2 = 48 393 + 0;
- 48 393 ÷ 2 = 24 196 + 1;
- 24 196 ÷ 2 = 12 098 + 0;
- 12 098 ÷ 2 = 6 049 + 0;
- 6 049 ÷ 2 = 3 024 + 1;
- 3 024 ÷ 2 = 1 512 + 0;
- 1 512 ÷ 2 = 756 + 0;
- 756 ÷ 2 = 378 + 0;
- 378 ÷ 2 = 189 + 0;
- 189 ÷ 2 = 94 + 1;
- 94 ÷ 2 = 47 + 0;
- 47 ÷ 2 = 23 + 1;
- 23 ÷ 2 = 11 + 1;
- 11 ÷ 2 = 5 + 1;
- 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.
1 585 743 880(10) = 101 1110 1000 0100 1000 1000 0000 1000(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 31.
- 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; ...
- The first bit (the leftmost) indicates the sign:
- 0 = positive integer number, 1 = negative integer number
The least number that is:
1) a power of 2
2) and is larger than the actual length, 31,
3) so that the first bit (leftmost) could be zero
(we deal with a positive number at this moment)
=== is: 32.
5. Get the 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.
1 585 743 880(10) = 0101 1110 1000 0100 1000 1000 0000 1000
6. Get the negative integer number representation. Part 1:
- To write the negative integer number on 32 bits (4 Bytes), as a signed binary in one's complement representation, replace all the bits on 0 with 1s and all the bits set on 1 with 0s.
Reverse the digits, flip the digits:
Replace the bits set on 0 with 1s and the bits set on 1 with 0s.
!(0101 1110 1000 0100 1000 1000 0000 1000)
= 1010 0001 0111 1011 0111 0111 1111 0111
7. Get the negative integer number representation. Part 2:
- To write the negative integer number on 32 bits (4 Bytes), as a signed binary in two's complement representation, add 1 to the number calculated above 1010 0001 0111 1011 0111 0111 1111 0111 (to the signed binary in one's complement representation).
Binary addition carries on a value of 2:
- 0 + 0 = 0
- 0 + 1 = 1
- 1 + 1 = 10
- 1 + 10 = 11
- 1 + 11 = 100
Add 1 to the number calculated above
(to the signed binary number in one's complement representation):
-1 585 743 880 =
1010 0001 0111 1011 0111 0111 1111 0111 + 1
Decimal Number -1 585 743 880(10) converted to signed binary in two's complement representation:
-1 585 743 880(10) = 1010 0001 0111 1011 0111 0111 1111 1000
Spaces were used to group digits: for binary, by 4, for decimal, by 3.