What are the required steps to convert base 10 integer
number -1 431 655 995 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:
|-1 431 655 995| = 1 431 655 995
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;
- 1 431 655 995 ÷ 2 = 715 827 997 + 1;
- 715 827 997 ÷ 2 = 357 913 998 + 1;
- 357 913 998 ÷ 2 = 178 956 999 + 0;
- 178 956 999 ÷ 2 = 89 478 499 + 1;
- 89 478 499 ÷ 2 = 44 739 249 + 1;
- 44 739 249 ÷ 2 = 22 369 624 + 1;
- 22 369 624 ÷ 2 = 11 184 812 + 0;
- 11 184 812 ÷ 2 = 5 592 406 + 0;
- 5 592 406 ÷ 2 = 2 796 203 + 0;
- 2 796 203 ÷ 2 = 1 398 101 + 1;
- 1 398 101 ÷ 2 = 699 050 + 1;
- 699 050 ÷ 2 = 349 525 + 0;
- 349 525 ÷ 2 = 174 762 + 1;
- 174 762 ÷ 2 = 87 381 + 0;
- 87 381 ÷ 2 = 43 690 + 1;
- 43 690 ÷ 2 = 21 845 + 0;
- 21 845 ÷ 2 = 10 922 + 1;
- 10 922 ÷ 2 = 5 461 + 0;
- 5 461 ÷ 2 = 2 730 + 1;
- 2 730 ÷ 2 = 1 365 + 0;
- 1 365 ÷ 2 = 682 + 1;
- 682 ÷ 2 = 341 + 0;
- 341 ÷ 2 = 170 + 1;
- 170 ÷ 2 = 85 + 0;
- 85 ÷ 2 = 42 + 1;
- 42 ÷ 2 = 21 + 0;
- 21 ÷ 2 = 10 + 1;
- 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.
1 431 655 995(10) = 101 0101 0101 0101 0101 0110 0011 1011(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:
1 431 655 995(10) = 0101 0101 0101 0101 0101 0110 0011 1011
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...
-1 431 655 995(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-1 431 655 995(10) = 1101 0101 0101 0101 0101 0110 0011 1011
Spaces were used to group digits: for binary, by 4, for decimal, by 3.