Convert -274 877 906 888 to a Signed Binary in Two's (2's) Complement Representation
How to convert decimal number -274 877 906 888(10) to a signed binary in two's (2's) complement representation
What are the steps to convert decimal number
-274 877 906 888 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:
|-274 877 906 888| = 274 877 906 888
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;
- 274 877 906 888 ÷ 2 = 137 438 953 444 + 0;
- 137 438 953 444 ÷ 2 = 68 719 476 722 + 0;
- 68 719 476 722 ÷ 2 = 34 359 738 361 + 0;
- 34 359 738 361 ÷ 2 = 17 179 869 180 + 1;
- 17 179 869 180 ÷ 2 = 8 589 934 590 + 0;
- 8 589 934 590 ÷ 2 = 4 294 967 295 + 0;
- 4 294 967 295 ÷ 2 = 2 147 483 647 + 1;
- 2 147 483 647 ÷ 2 = 1 073 741 823 + 1;
- 1 073 741 823 ÷ 2 = 536 870 911 + 1;
- 536 870 911 ÷ 2 = 268 435 455 + 1;
- 268 435 455 ÷ 2 = 134 217 727 + 1;
- 134 217 727 ÷ 2 = 67 108 863 + 1;
- 67 108 863 ÷ 2 = 33 554 431 + 1;
- 33 554 431 ÷ 2 = 16 777 215 + 1;
- 16 777 215 ÷ 2 = 8 388 607 + 1;
- 8 388 607 ÷ 2 = 4 194 303 + 1;
- 4 194 303 ÷ 2 = 2 097 151 + 1;
- 2 097 151 ÷ 2 = 1 048 575 + 1;
- 1 048 575 ÷ 2 = 524 287 + 1;
- 524 287 ÷ 2 = 262 143 + 1;
- 262 143 ÷ 2 = 131 071 + 1;
- 131 071 ÷ 2 = 65 535 + 1;
- 65 535 ÷ 2 = 32 767 + 1;
- 32 767 ÷ 2 = 16 383 + 1;
- 16 383 ÷ 2 = 8 191 + 1;
- 8 191 ÷ 2 = 4 095 + 1;
- 4 095 ÷ 2 = 2 047 + 1;
- 2 047 ÷ 2 = 1 023 + 1;
- 1 023 ÷ 2 = 511 + 1;
- 511 ÷ 2 = 255 + 1;
- 255 ÷ 2 = 127 + 1;
- 127 ÷ 2 = 63 + 1;
- 63 ÷ 2 = 31 + 1;
- 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.
274 877 906 888(10) = 11 1111 1111 1111 1111 1111 1111 1111 1100 1000(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 38.
- 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, 38,
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.
274 877 906 888(10) = 0000 0000 0000 0000 0000 0000 0011 1111 1111 1111 1111 1111 1111 1111 1100 1000
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 0011 1111 1111 1111 1111 1111 1111 1111 1100 1000)
= 1111 1111 1111 1111 1111 1111 1100 0000 0000 0000 0000 0000 0000 0000 0011 0111
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 1100 0000 0000 0000 0000 0000 0000 0000 0011 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):
-274 877 906 888 =
1111 1111 1111 1111 1111 1111 1100 0000 0000 0000 0000 0000 0000 0000 0011 0111 + 1
Decimal Number -274 877 906 888(10) converted to signed binary in two's complement representation:
-274 877 906 888(10) = 1111 1111 1111 1111 1111 1111 1100 0000 0000 0000 0000 0000 0000 0000 0011 1000
Spaces were used to group digits: for binary, by 4, for decimal, by 3.