Convert -1 073 741 815 to a Signed Binary in Two's (2's) Complement Representation
How to convert decimal number -1 073 741 815(10) to a signed binary in two's (2's) complement representation
What are the steps to convert decimal number
-1 073 741 815 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:
|-1 073 741 815| = 1 073 741 815
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;
- 1 073 741 815 ÷ 2 = 536 870 907 + 1;
- 536 870 907 ÷ 2 = 268 435 453 + 1;
- 268 435 453 ÷ 2 = 134 217 726 + 1;
- 134 217 726 ÷ 2 = 67 108 863 + 0;
- 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.
1 073 741 815(10) = 11 1111 1111 1111 1111 1111 1111 0111(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 30.
- 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, 30,
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.
1 073 741 815(10) = 0011 1111 1111 1111 1111 1111 1111 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.
!(0011 1111 1111 1111 1111 1111 1111 0111)
= 1100 0000 0000 0000 0000 0000 0000 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 1100 0000 0000 0000 0000 0000 0000 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):
-1 073 741 815 =
1100 0000 0000 0000 0000 0000 0000 1000 + 1
Decimal Number -1 073 741 815(10) converted to signed binary in two's complement representation:
-1 073 741 815(10) = 1100 0000 0000 0000 0000 0000 0000 1001
Spaces were used to group digits: for binary, by 4, for decimal, by 3.