What are the required steps to convert base 10 integer
number -2 684 503 431 to signed binary code (in base 2)?
- 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:
|-2 684 503 431| = 2 684 503 431
2. Divide the number repeatedly by 2:
Keep track of each remainder.
Stop when you get a quotient that is equal to zero.
- division = quotient + remainder;
- 2 684 503 431 ÷ 2 = 1 342 251 715 + 1;
- 1 342 251 715 ÷ 2 = 671 125 857 + 1;
- 671 125 857 ÷ 2 = 335 562 928 + 1;
- 335 562 928 ÷ 2 = 167 781 464 + 0;
- 167 781 464 ÷ 2 = 83 890 732 + 0;
- 83 890 732 ÷ 2 = 41 945 366 + 0;
- 41 945 366 ÷ 2 = 20 972 683 + 0;
- 20 972 683 ÷ 2 = 10 486 341 + 1;
- 10 486 341 ÷ 2 = 5 243 170 + 1;
- 5 243 170 ÷ 2 = 2 621 585 + 0;
- 2 621 585 ÷ 2 = 1 310 792 + 1;
- 1 310 792 ÷ 2 = 655 396 + 0;
- 655 396 ÷ 2 = 327 698 + 0;
- 327 698 ÷ 2 = 163 849 + 0;
- 163 849 ÷ 2 = 81 924 + 1;
- 81 924 ÷ 2 = 40 962 + 0;
- 40 962 ÷ 2 = 20 481 + 0;
- 20 481 ÷ 2 = 10 240 + 1;
- 10 240 ÷ 2 = 5 120 + 0;
- 5 120 ÷ 2 = 2 560 + 0;
- 2 560 ÷ 2 = 1 280 + 0;
- 1 280 ÷ 2 = 640 + 0;
- 640 ÷ 2 = 320 + 0;
- 320 ÷ 2 = 160 + 0;
- 160 ÷ 2 = 80 + 0;
- 80 ÷ 2 = 40 + 0;
- 40 ÷ 2 = 20 + 0;
- 20 ÷ 2 = 10 + 0;
- 10 ÷ 2 = 5 + 0;
- 5 ÷ 2 = 2 + 1;
- 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.
2 684 503 431(10) = 1010 0000 0000 0010 0100 0101 1000 0111(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) is reserved for 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:
2 684 503 431(10) = 0000 0000 0000 0000 0000 0000 0000 0000 1010 0000 0000 0010 0100 0101 1000 0111
6. Get the negative integer number representation:
To get the negative integer number representation on 64 bits (8 Bytes),
... change the first bit (the leftmost), from 0 to 1...
-2 684 503 431(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-2 684 503 431(10) = 1000 0000 0000 0000 0000 0000 0000 0000 1010 0000 0000 0010 0100 0101 1000 0111
Spaces were used to group digits: for binary, by 4, for decimal, by 3.