Convert -1 869 596 785 to a Signed Binary in Two's (2's) Complement Representation
How to convert decimal number -1 869 596 785(10) to a signed binary in two's (2's) complement representation
What are the steps to convert decimal number
-1 869 596 785 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:
|-1 869 596 785| = 1 869 596 785
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;
- 1 869 596 785 ÷ 2 = 934 798 392 + 1;
- 934 798 392 ÷ 2 = 467 399 196 + 0;
- 467 399 196 ÷ 2 = 233 699 598 + 0;
- 233 699 598 ÷ 2 = 116 849 799 + 0;
- 116 849 799 ÷ 2 = 58 424 899 + 1;
- 58 424 899 ÷ 2 = 29 212 449 + 1;
- 29 212 449 ÷ 2 = 14 606 224 + 1;
- 14 606 224 ÷ 2 = 7 303 112 + 0;
- 7 303 112 ÷ 2 = 3 651 556 + 0;
- 3 651 556 ÷ 2 = 1 825 778 + 0;
- 1 825 778 ÷ 2 = 912 889 + 0;
- 912 889 ÷ 2 = 456 444 + 1;
- 456 444 ÷ 2 = 228 222 + 0;
- 228 222 ÷ 2 = 114 111 + 0;
- 114 111 ÷ 2 = 57 055 + 1;
- 57 055 ÷ 2 = 28 527 + 1;
- 28 527 ÷ 2 = 14 263 + 1;
- 14 263 ÷ 2 = 7 131 + 1;
- 7 131 ÷ 2 = 3 565 + 1;
- 3 565 ÷ 2 = 1 782 + 1;
- 1 782 ÷ 2 = 891 + 0;
- 891 ÷ 2 = 445 + 1;
- 445 ÷ 2 = 222 + 1;
- 222 ÷ 2 = 111 + 0;
- 111 ÷ 2 = 55 + 1;
- 55 ÷ 2 = 27 + 1;
- 27 ÷ 2 = 13 + 1;
- 13 ÷ 2 = 6 + 1;
- 6 ÷ 2 = 3 + 0;
- 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.
1 869 596 785(10) = 110 1111 0110 1111 1100 1000 0111 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.
1 869 596 785(10) = 0110 1111 0110 1111 1100 1000 0111 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.
!(0110 1111 0110 1111 1100 1000 0111 0001)
= 1001 0000 1001 0000 0011 0111 1000 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 1001 0000 1001 0000 0011 0111 1000 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):
-1 869 596 785 =
1001 0000 1001 0000 0011 0111 1000 1110 + 1
Decimal Number -1 869 596 785(10) converted to signed binary in two's complement representation:
-1 869 596 785(10) = 1001 0000 1001 0000 0011 0111 1000 1111
Spaces were used to group digits: for binary, by 4, for decimal, by 3.