Convert -2 684 354 425 to a Signed Binary in Two's (2's) Complement Representation
How to convert decimal number -2 684 354 425(10) to a signed binary in two's (2's) complement representation
What are the steps to convert decimal number
-2 684 354 425 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:
|-2 684 354 425| = 2 684 354 425
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;
- 2 684 354 425 ÷ 2 = 1 342 177 212 + 1;
- 1 342 177 212 ÷ 2 = 671 088 606 + 0;
- 671 088 606 ÷ 2 = 335 544 303 + 0;
- 335 544 303 ÷ 2 = 167 772 151 + 1;
- 167 772 151 ÷ 2 = 83 886 075 + 1;
- 83 886 075 ÷ 2 = 41 943 037 + 1;
- 41 943 037 ÷ 2 = 20 971 518 + 1;
- 20 971 518 ÷ 2 = 10 485 759 + 0;
- 10 485 759 ÷ 2 = 5 242 879 + 1;
- 5 242 879 ÷ 2 = 2 621 439 + 1;
- 2 621 439 ÷ 2 = 1 310 719 + 1;
- 1 310 719 ÷ 2 = 655 359 + 1;
- 655 359 ÷ 2 = 327 679 + 1;
- 327 679 ÷ 2 = 163 839 + 1;
- 163 839 ÷ 2 = 81 919 + 1;
- 81 919 ÷ 2 = 40 959 + 1;
- 40 959 ÷ 2 = 20 479 + 1;
- 20 479 ÷ 2 = 10 239 + 1;
- 10 239 ÷ 2 = 5 119 + 1;
- 5 119 ÷ 2 = 2 559 + 1;
- 2 559 ÷ 2 = 1 279 + 1;
- 1 279 ÷ 2 = 639 + 1;
- 639 ÷ 2 = 319 + 1;
- 319 ÷ 2 = 159 + 1;
- 159 ÷ 2 = 79 + 1;
- 79 ÷ 2 = 39 + 1;
- 39 ÷ 2 = 19 + 1;
- 19 ÷ 2 = 9 + 1;
- 9 ÷ 2 = 4 + 1;
- 4 ÷ 2 = 2 + 0;
- 2 ÷ 2 = 1 + 0;
- 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.
2 684 354 425(10) = 1001 1111 1111 1111 1111 1111 0111 1001(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 32.
- 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, 32,
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.
2 684 354 425(10) = 0000 0000 0000 0000 0000 0000 0000 0000 1001 1111 1111 1111 1111 1111 0111 1001
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 0000 0000 1001 1111 1111 1111 1111 1111 0111 1001)
= 1111 1111 1111 1111 1111 1111 1111 1111 0110 0000 0000 0000 0000 0000 1000 0110
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 1111 1111 0110 0000 0000 0000 0000 0000 1000 0110 (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):
-2 684 354 425 =
1111 1111 1111 1111 1111 1111 1111 1111 0110 0000 0000 0000 0000 0000 1000 0110 + 1
Decimal Number -2 684 354 425(10) converted to signed binary in two's complement representation:
-2 684 354 425(10) = 1111 1111 1111 1111 1111 1111 1111 1111 0110 0000 0000 0000 0000 0000 1000 0111
Spaces were used to group digits: for binary, by 4, for decimal, by 3.