What are the required steps to convert base 10 integer
number -1 391 460 213 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:
|-1 391 460 213| = 1 391 460 213
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;
- 1 391 460 213 ÷ 2 = 695 730 106 + 1;
- 695 730 106 ÷ 2 = 347 865 053 + 0;
- 347 865 053 ÷ 2 = 173 932 526 + 1;
- 173 932 526 ÷ 2 = 86 966 263 + 0;
- 86 966 263 ÷ 2 = 43 483 131 + 1;
- 43 483 131 ÷ 2 = 21 741 565 + 1;
- 21 741 565 ÷ 2 = 10 870 782 + 1;
- 10 870 782 ÷ 2 = 5 435 391 + 0;
- 5 435 391 ÷ 2 = 2 717 695 + 1;
- 2 717 695 ÷ 2 = 1 358 847 + 1;
- 1 358 847 ÷ 2 = 679 423 + 1;
- 679 423 ÷ 2 = 339 711 + 1;
- 339 711 ÷ 2 = 169 855 + 1;
- 169 855 ÷ 2 = 84 927 + 1;
- 84 927 ÷ 2 = 42 463 + 1;
- 42 463 ÷ 2 = 21 231 + 1;
- 21 231 ÷ 2 = 10 615 + 1;
- 10 615 ÷ 2 = 5 307 + 1;
- 5 307 ÷ 2 = 2 653 + 1;
- 2 653 ÷ 2 = 1 326 + 1;
- 1 326 ÷ 2 = 663 + 0;
- 663 ÷ 2 = 331 + 1;
- 331 ÷ 2 = 165 + 1;
- 165 ÷ 2 = 82 + 1;
- 82 ÷ 2 = 41 + 0;
- 41 ÷ 2 = 20 + 1;
- 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.
1 391 460 213(10) = 101 0010 1110 1111 1111 1111 0111 0101(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 31.
- 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, 31,
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:
1 391 460 213(10) = 0101 0010 1110 1111 1111 1111 0111 0101
6. Get the negative integer number representation:
To get the negative integer number representation on 32 bits (4 Bytes),
... change the first bit (the leftmost), from 0 to 1...
-1 391 460 213(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-1 391 460 213(10) = 1101 0010 1110 1111 1111 1111 0111 0101
Spaces were used to group digits: for binary, by 4, for decimal, by 3.