Convert -135 291 469 777 to a Signed Binary in Two's (2's) Complement Representation
How to convert decimal number -135 291 469 777(10) to a signed binary in two's (2's) complement representation
What are the steps to convert decimal number
-135 291 469 777 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:
|-135 291 469 777| = 135 291 469 777
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;
- 135 291 469 777 ÷ 2 = 67 645 734 888 + 1;
- 67 645 734 888 ÷ 2 = 33 822 867 444 + 0;
- 33 822 867 444 ÷ 2 = 16 911 433 722 + 0;
- 16 911 433 722 ÷ 2 = 8 455 716 861 + 0;
- 8 455 716 861 ÷ 2 = 4 227 858 430 + 1;
- 4 227 858 430 ÷ 2 = 2 113 929 215 + 0;
- 2 113 929 215 ÷ 2 = 1 056 964 607 + 1;
- 1 056 964 607 ÷ 2 = 528 482 303 + 1;
- 528 482 303 ÷ 2 = 264 241 151 + 1;
- 264 241 151 ÷ 2 = 132 120 575 + 1;
- 132 120 575 ÷ 2 = 66 060 287 + 1;
- 66 060 287 ÷ 2 = 33 030 143 + 1;
- 33 030 143 ÷ 2 = 16 515 071 + 1;
- 16 515 071 ÷ 2 = 8 257 535 + 1;
- 8 257 535 ÷ 2 = 4 128 767 + 1;
- 4 128 767 ÷ 2 = 2 064 383 + 1;
- 2 064 383 ÷ 2 = 1 032 191 + 1;
- 1 032 191 ÷ 2 = 516 095 + 1;
- 516 095 ÷ 2 = 258 047 + 1;
- 258 047 ÷ 2 = 129 023 + 1;
- 129 023 ÷ 2 = 64 511 + 1;
- 64 511 ÷ 2 = 32 255 + 1;
- 32 255 ÷ 2 = 16 127 + 1;
- 16 127 ÷ 2 = 8 063 + 1;
- 8 063 ÷ 2 = 4 031 + 1;
- 4 031 ÷ 2 = 2 015 + 1;
- 2 015 ÷ 2 = 1 007 + 1;
- 1 007 ÷ 2 = 503 + 1;
- 503 ÷ 2 = 251 + 1;
- 251 ÷ 2 = 125 + 1;
- 125 ÷ 2 = 62 + 1;
- 62 ÷ 2 = 31 + 0;
- 31 ÷ 2 = 15 + 1;
- 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.
135 291 469 777(10) = 1 1111 0111 1111 1111 1111 1111 1111 1101 0001(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 37.
- 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, 37,
3) so that the first bit (leftmost) could be zero
(we deal with a positive number at this moment)
=== is: 64.
5. Get the positive binary computer representation on 64 bits (8 Bytes):
If needed, add extra 0s in front (to the left) of the base 2 number, up to the required length, 64.
135 291 469 777(10) = 0000 0000 0000 0000 0000 0000 0001 1111 0111 1111 1111 1111 1111 1111 1101 0001
6. Get the negative integer number representation. Part 1:
- To write the negative integer number on 64 bits (8 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.
!(0000 0000 0000 0000 0000 0000 0001 1111 0111 1111 1111 1111 1111 1111 1101 0001)
= 1111 1111 1111 1111 1111 1111 1110 0000 1000 0000 0000 0000 0000 0000 0010 1110
7. Get the negative integer number representation. Part 2:
- To write the negative integer number on 64 bits (8 Bytes), as a signed binary in two's complement representation, add 1 to the number calculated above 1111 1111 1111 1111 1111 1111 1110 0000 1000 0000 0000 0000 0000 0000 0010 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):
-135 291 469 777 =
1111 1111 1111 1111 1111 1111 1110 0000 1000 0000 0000 0000 0000 0000 0010 1110 + 1
Decimal Number -135 291 469 777(10) converted to signed binary in two's complement representation:
-135 291 469 777(10) = 1111 1111 1111 1111 1111 1111 1110 0000 1000 0000 0000 0000 0000 0000 0010 1111
Spaces were used to group digits: for binary, by 4, for decimal, by 3.