Convert -1 073 741 873 to a Signed Binary in Two's (2's) Complement Representation
How to convert decimal number -1 073 741 873(10) to a signed binary in two's (2's) complement representation
What are the steps to convert decimal number
-1 073 741 873 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:
|-1 073 741 873| = 1 073 741 873
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;
- 1 073 741 873 ÷ 2 = 536 870 936 + 1;
- 536 870 936 ÷ 2 = 268 435 468 + 0;
- 268 435 468 ÷ 2 = 134 217 734 + 0;
- 134 217 734 ÷ 2 = 67 108 867 + 0;
- 67 108 867 ÷ 2 = 33 554 433 + 1;
- 33 554 433 ÷ 2 = 16 777 216 + 1;
- 16 777 216 ÷ 2 = 8 388 608 + 0;
- 8 388 608 ÷ 2 = 4 194 304 + 0;
- 4 194 304 ÷ 2 = 2 097 152 + 0;
- 2 097 152 ÷ 2 = 1 048 576 + 0;
- 1 048 576 ÷ 2 = 524 288 + 0;
- 524 288 ÷ 2 = 262 144 + 0;
- 262 144 ÷ 2 = 131 072 + 0;
- 131 072 ÷ 2 = 65 536 + 0;
- 65 536 ÷ 2 = 32 768 + 0;
- 32 768 ÷ 2 = 16 384 + 0;
- 16 384 ÷ 2 = 8 192 + 0;
- 8 192 ÷ 2 = 4 096 + 0;
- 4 096 ÷ 2 = 2 048 + 0;
- 2 048 ÷ 2 = 1 024 + 0;
- 1 024 ÷ 2 = 512 + 0;
- 512 ÷ 2 = 256 + 0;
- 256 ÷ 2 = 128 + 0;
- 128 ÷ 2 = 64 + 0;
- 64 ÷ 2 = 32 + 0;
- 32 ÷ 2 = 16 + 0;
- 16 ÷ 2 = 8 + 0;
- 8 ÷ 2 = 4 + 0;
- 4 ÷ 2 = 2 + 0;
- 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.
1 073 741 873(10) = 100 0000 0000 0000 0000 0000 0011 0001(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.
1 073 741 873(10) = 0100 0000 0000 0000 0000 0000 0011 0001
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.
!(0100 0000 0000 0000 0000 0000 0011 0001)
= 1011 1111 1111 1111 1111 1111 1100 1110
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 1011 1111 1111 1111 1111 1111 1100 1110 (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):
-1 073 741 873 =
1011 1111 1111 1111 1111 1111 1100 1110 + 1
Decimal Number -1 073 741 873(10) converted to signed binary in two's complement representation:
-1 073 741 873(10) = 1011 1111 1111 1111 1111 1111 1100 1111
Spaces were used to group digits: for binary, by 4, for decimal, by 3.