Convert -1 985 229 415 to a Signed Binary in Two's (2's) Complement Representation
How to convert decimal number -1 985 229 415(10) to a signed binary in two's (2's) complement representation
What are the steps to convert decimal number
-1 985 229 415 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:
|-1 985 229 415| = 1 985 229 415
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;
- 1 985 229 415 ÷ 2 = 992 614 707 + 1;
- 992 614 707 ÷ 2 = 496 307 353 + 1;
- 496 307 353 ÷ 2 = 248 153 676 + 1;
- 248 153 676 ÷ 2 = 124 076 838 + 0;
- 124 076 838 ÷ 2 = 62 038 419 + 0;
- 62 038 419 ÷ 2 = 31 019 209 + 1;
- 31 019 209 ÷ 2 = 15 509 604 + 1;
- 15 509 604 ÷ 2 = 7 754 802 + 0;
- 7 754 802 ÷ 2 = 3 877 401 + 0;
- 3 877 401 ÷ 2 = 1 938 700 + 1;
- 1 938 700 ÷ 2 = 969 350 + 0;
- 969 350 ÷ 2 = 484 675 + 0;
- 484 675 ÷ 2 = 242 337 + 1;
- 242 337 ÷ 2 = 121 168 + 1;
- 121 168 ÷ 2 = 60 584 + 0;
- 60 584 ÷ 2 = 30 292 + 0;
- 30 292 ÷ 2 = 15 146 + 0;
- 15 146 ÷ 2 = 7 573 + 0;
- 7 573 ÷ 2 = 3 786 + 1;
- 3 786 ÷ 2 = 1 893 + 0;
- 1 893 ÷ 2 = 946 + 1;
- 946 ÷ 2 = 473 + 0;
- 473 ÷ 2 = 236 + 1;
- 236 ÷ 2 = 118 + 0;
- 118 ÷ 2 = 59 + 0;
- 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.
1 985 229 415(10) = 111 0110 0101 0100 0011 0010 0110 0111(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.
1 985 229 415(10) = 0111 0110 0101 0100 0011 0010 0110 0111
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.
!(0111 0110 0101 0100 0011 0010 0110 0111)
= 1000 1001 1010 1011 1100 1101 1001 1000
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 1000 1001 1010 1011 1100 1101 1001 1000 (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):
-1 985 229 415 =
1000 1001 1010 1011 1100 1101 1001 1000 + 1
Decimal Number -1 985 229 415(10) converted to signed binary in two's complement representation:
-1 985 229 415(10) = 1000 1001 1010 1011 1100 1101 1001 1001
Spaces were used to group digits: for binary, by 4, for decimal, by 3.