What are the required steps to convert base 10 integer
number -1 770 909 331 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:
|-1 770 909 331| = 1 770 909 331
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;
- 1 770 909 331 ÷ 2 = 885 454 665 + 1;
- 885 454 665 ÷ 2 = 442 727 332 + 1;
- 442 727 332 ÷ 2 = 221 363 666 + 0;
- 221 363 666 ÷ 2 = 110 681 833 + 0;
- 110 681 833 ÷ 2 = 55 340 916 + 1;
- 55 340 916 ÷ 2 = 27 670 458 + 0;
- 27 670 458 ÷ 2 = 13 835 229 + 0;
- 13 835 229 ÷ 2 = 6 917 614 + 1;
- 6 917 614 ÷ 2 = 3 458 807 + 0;
- 3 458 807 ÷ 2 = 1 729 403 + 1;
- 1 729 403 ÷ 2 = 864 701 + 1;
- 864 701 ÷ 2 = 432 350 + 1;
- 432 350 ÷ 2 = 216 175 + 0;
- 216 175 ÷ 2 = 108 087 + 1;
- 108 087 ÷ 2 = 54 043 + 1;
- 54 043 ÷ 2 = 27 021 + 1;
- 27 021 ÷ 2 = 13 510 + 1;
- 13 510 ÷ 2 = 6 755 + 0;
- 6 755 ÷ 2 = 3 377 + 1;
- 3 377 ÷ 2 = 1 688 + 1;
- 1 688 ÷ 2 = 844 + 0;
- 844 ÷ 2 = 422 + 0;
- 422 ÷ 2 = 211 + 0;
- 211 ÷ 2 = 105 + 1;
- 105 ÷ 2 = 52 + 1;
- 52 ÷ 2 = 26 + 0;
- 26 ÷ 2 = 13 + 0;
- 13 ÷ 2 = 6 + 1;
- 6 ÷ 2 = 3 + 0;
- 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.
1 770 909 331(10) = 110 1001 1000 1101 1110 1110 1001 0011(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:
1 770 909 331(10) = 0110 1001 1000 1101 1110 1110 1001 0011
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...
-1 770 909 331(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-1 770 909 331(10) = 1110 1001 1000 1101 1110 1110 1001 0011
Spaces were used to group digits: for binary, by 4, for decimal, by 3.