What are the required steps to convert base 10 integer
number -1 140 850 640 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:
|-1 140 850 640| = 1 140 850 640
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;
- 1 140 850 640 ÷ 2 = 570 425 320 + 0;
- 570 425 320 ÷ 2 = 285 212 660 + 0;
- 285 212 660 ÷ 2 = 142 606 330 + 0;
- 142 606 330 ÷ 2 = 71 303 165 + 0;
- 71 303 165 ÷ 2 = 35 651 582 + 1;
- 35 651 582 ÷ 2 = 17 825 791 + 0;
- 17 825 791 ÷ 2 = 8 912 895 + 1;
- 8 912 895 ÷ 2 = 4 456 447 + 1;
- 4 456 447 ÷ 2 = 2 228 223 + 1;
- 2 228 223 ÷ 2 = 1 114 111 + 1;
- 1 114 111 ÷ 2 = 557 055 + 1;
- 557 055 ÷ 2 = 278 527 + 1;
- 278 527 ÷ 2 = 139 263 + 1;
- 139 263 ÷ 2 = 69 631 + 1;
- 69 631 ÷ 2 = 34 815 + 1;
- 34 815 ÷ 2 = 17 407 + 1;
- 17 407 ÷ 2 = 8 703 + 1;
- 8 703 ÷ 2 = 4 351 + 1;
- 4 351 ÷ 2 = 2 175 + 1;
- 2 175 ÷ 2 = 1 087 + 1;
- 1 087 ÷ 2 = 543 + 1;
- 543 ÷ 2 = 271 + 1;
- 271 ÷ 2 = 135 + 1;
- 135 ÷ 2 = 67 + 1;
- 67 ÷ 2 = 33 + 1;
- 33 ÷ 2 = 16 + 1;
- 16 ÷ 2 = 8 + 0;
- 8 ÷ 2 = 4 + 0;
- 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.
1 140 850 640(10) = 100 0011 1111 1111 1111 1111 1101 0000(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:
1 140 850 640(10) = 0100 0011 1111 1111 1111 1111 1101 0000
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...
-1 140 850 640(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-1 140 850 640(10) = 1100 0011 1111 1111 1111 1111 1101 0000
Spaces were used to group digits: for binary, by 4, for decimal, by 3.