What are the required steps to convert base 10 integer
number -955 531 881 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:
|-955 531 881| = 955 531 881
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;
- 955 531 881 ÷ 2 = 477 765 940 + 1;
- 477 765 940 ÷ 2 = 238 882 970 + 0;
- 238 882 970 ÷ 2 = 119 441 485 + 0;
- 119 441 485 ÷ 2 = 59 720 742 + 1;
- 59 720 742 ÷ 2 = 29 860 371 + 0;
- 29 860 371 ÷ 2 = 14 930 185 + 1;
- 14 930 185 ÷ 2 = 7 465 092 + 1;
- 7 465 092 ÷ 2 = 3 732 546 + 0;
- 3 732 546 ÷ 2 = 1 866 273 + 0;
- 1 866 273 ÷ 2 = 933 136 + 1;
- 933 136 ÷ 2 = 466 568 + 0;
- 466 568 ÷ 2 = 233 284 + 0;
- 233 284 ÷ 2 = 116 642 + 0;
- 116 642 ÷ 2 = 58 321 + 0;
- 58 321 ÷ 2 = 29 160 + 1;
- 29 160 ÷ 2 = 14 580 + 0;
- 14 580 ÷ 2 = 7 290 + 0;
- 7 290 ÷ 2 = 3 645 + 0;
- 3 645 ÷ 2 = 1 822 + 1;
- 1 822 ÷ 2 = 911 + 0;
- 911 ÷ 2 = 455 + 1;
- 455 ÷ 2 = 227 + 1;
- 227 ÷ 2 = 113 + 1;
- 113 ÷ 2 = 56 + 1;
- 56 ÷ 2 = 28 + 0;
- 28 ÷ 2 = 14 + 0;
- 14 ÷ 2 = 7 + 0;
- 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.
955 531 881(10) = 11 1000 1111 0100 0100 0010 0110 1001(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) 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, 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:
955 531 881(10) = 0011 1000 1111 0100 0100 0010 0110 1001
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...
-955 531 881(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-955 531 881(10) = 1011 1000 1111 0100 0100 0010 0110 1001
Spaces were used to group digits: for binary, by 4, for decimal, by 3.