What are the required steps to convert base 10 integer
number -109 209 807 347 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:
|-109 209 807 347| = 109 209 807 347
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;
- 109 209 807 347 ÷ 2 = 54 604 903 673 + 1;
- 54 604 903 673 ÷ 2 = 27 302 451 836 + 1;
- 27 302 451 836 ÷ 2 = 13 651 225 918 + 0;
- 13 651 225 918 ÷ 2 = 6 825 612 959 + 0;
- 6 825 612 959 ÷ 2 = 3 412 806 479 + 1;
- 3 412 806 479 ÷ 2 = 1 706 403 239 + 1;
- 1 706 403 239 ÷ 2 = 853 201 619 + 1;
- 853 201 619 ÷ 2 = 426 600 809 + 1;
- 426 600 809 ÷ 2 = 213 300 404 + 1;
- 213 300 404 ÷ 2 = 106 650 202 + 0;
- 106 650 202 ÷ 2 = 53 325 101 + 0;
- 53 325 101 ÷ 2 = 26 662 550 + 1;
- 26 662 550 ÷ 2 = 13 331 275 + 0;
- 13 331 275 ÷ 2 = 6 665 637 + 1;
- 6 665 637 ÷ 2 = 3 332 818 + 1;
- 3 332 818 ÷ 2 = 1 666 409 + 0;
- 1 666 409 ÷ 2 = 833 204 + 1;
- 833 204 ÷ 2 = 416 602 + 0;
- 416 602 ÷ 2 = 208 301 + 0;
- 208 301 ÷ 2 = 104 150 + 1;
- 104 150 ÷ 2 = 52 075 + 0;
- 52 075 ÷ 2 = 26 037 + 1;
- 26 037 ÷ 2 = 13 018 + 1;
- 13 018 ÷ 2 = 6 509 + 0;
- 6 509 ÷ 2 = 3 254 + 1;
- 3 254 ÷ 2 = 1 627 + 0;
- 1 627 ÷ 2 = 813 + 1;
- 813 ÷ 2 = 406 + 1;
- 406 ÷ 2 = 203 + 0;
- 203 ÷ 2 = 101 + 1;
- 101 ÷ 2 = 50 + 1;
- 50 ÷ 2 = 25 + 0;
- 25 ÷ 2 = 12 + 1;
- 12 ÷ 2 = 6 + 0;
- 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.
109 209 807 347(10) = 1 1001 0110 1101 0110 1001 0110 1001 1111 0011(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 37.
- 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, 37,
3) so that the first bit (leftmost) could be zero
(we deal with a positive number at this moment)
=== is: 64.
5. Get the positive binary computer representation on 64 bits (8 Bytes):
If needed, add extra 0s in front (to the left) of the base 2 number, up to the required length, 64:
109 209 807 347(10) = 0000 0000 0000 0000 0000 0000 0001 1001 0110 1101 0110 1001 0110 1001 1111 0011
6. Get the negative integer number representation:
To get the negative integer number representation on 64 bits (8 Bytes),
... change the first bit (the leftmost), from 0 to 1...
-109 209 807 347(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-109 209 807 347(10) = 1000 0000 0000 0000 0000 0000 0001 1001 0110 1101 0110 1001 0110 1001 1111 0011
Spaces were used to group digits: for binary, by 4, for decimal, by 3.